Answer:
[tex]\frac{5x-4}{x(x^2+7)^2} = \frac{A}{x} + \frac{Bx+C}{x^2+7} + \frac{Dx+E}{(x^2+7)^2}[/tex]
Step-by-step explanation:
Given the expression [tex]\frac{5x-4}{x(x^2+7)^2}[/tex], we are to re-write the expression in form of a partial fraction.
Before we write in form of a partial fraction, we need to note the expression at the denominator. Since the expression in parenthesis is a quadratic equation, the equivalent numerator must be a linear expression.
Also the quadratic equation is a repeated form since it is squared. This means that we are to repeat the quadratic equation twice when writing as a partial fraction.
[tex]\frac{5x-4}{x(x^2+7)^2} = \frac{A}{x} + \frac{Bx+C}{x^2+7} + \frac{Dx+E}{(x^2+7)^2}[/tex]
From the above partial fraction, it can be seen that x² + 7 in parenthesis was repeated twice and their equivalent expressions at the numerator are both linear i.e Bx+E and Dx+ E where A, B, C, D and E are the unknown constant.
A test-preparation company advertises that its training program raises SAT scores by an average of at least 30 points. A random sample of test-takers who had completed the training showed a mean increase smaller than 30 points.
(a) Write the hypotheses for a left-tailed test of the mean.
(b) Explain the consequences of a Type I error in this context.
Answer:
(a) Null Hypothesis, [tex]H_0[/tex] : [tex]\mu \geq[/tex] 30 points
Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] < 30 points
(b) Type I error is that we conclude that test-takers who had completed the training showed a mean increase smaller than 30 points but in actual, the program raises SAT scores by an average of at least 30 points.
Step-by-step explanation:
We are given that a test-preparation company advertises that its training program raises SAT scores by an average of at least 30 points.
A random sample of test-takers who had completed the training showed a mean increase smaller than 30 points.
Let [tex]\mu[/tex] = average SAT score.
(a) So, Null Hypothesis, [tex]H_0[/tex] : [tex]\mu \geq[/tex] 30 points
Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] < 30 points
Here, the null hypothesis states that the training program raises SAT scores by an average of at least 30 points.
On the other hand, the alternate hypothesis states that test-takers who had completed the training showed a mean increase smaller than 30 points.
(b) Type I error states the probability of rejecting the null hypothesis given the fact that null hypothesis is true.
According to the question, the Type I error is that we conclude that test-takers who had completed the training showed a mean increase smaller than 30 points but in actual, the program raises SAT scores by an average of at least 30 points.
The consequence of a Type I error is that we conclude the test-takers have low SAT scores but in actual they have an SAT score of at least 30 points.
] You are scheduled to receive $20,000 in two years. When you receive it, you will invest it for six more years at 8.4 percent per year. How much will you have in eight years?
Answer:
32449.3
Step-by-step explanation:
use the formula A = P(1+r / 100)^t
20000 × (1+ (8.4 / 100))^6
=32449.3
h(x) = -x² + 3x + 10
Answer:
x = 5 or x = -2 or 3 - 2 x (derivative)
Step-by-step explanation:
Solve for x over the real numbers:
-x^2 + 3 x + 10 = 0
Multiply both sides by -1:
x^2 - 3 x - 10 = 0
x = (3 ± sqrt((-3)^2 - 4 (-10)))/2 = (3 ± sqrt(9 + 40))/2 = (3 ± sqrt(49))/2:
x = (3 + sqrt(49))/2 or x = (3 - sqrt(49))/2
sqrt(49) = sqrt(7^2) = 7:
x = (3 + 7)/2 or x = (3 - 7)/2
(3 + 7)/2 = 10/2 = 5:
x = 5 or x = (3 - 7)/2
(3 - 7)/2 = -4/2 = -2:
Answer: x = 5 or x = -2
____________________________________
Find the derivative of the following via implicit differentiation:
d/dx(H(x)) = d/dx(10 + 3 x - x^2)
Using the chain rule, d/dx(H(x)) = ( dH(u))/( du) ( du)/( dx), where u = x and d/( du)(H(u)) = H'(u):
(d/dx(x)) H'(x) = d/dx(10 + 3 x - x^2)
The derivative of x is 1:
1 H'(x) = d/dx(10 + 3 x - x^2)
Differentiate the sum term by term and factor out constants:
H'(x) = d/dx(10) + 3 (d/dx(x)) - d/dx(x^2)
The derivative of 10 is zero:
H'(x) = 3 (d/dx(x)) - d/dx(x^2) + 0
Simplify the expression:
H'(x) = 3 (d/dx(x)) - d/dx(x^2)
The derivative of x is 1:
H'(x) = -(d/dx(x^2)) + 1 3
Use the power rule, d/dx(x^n) = n x^(n - 1), where n = 2.
d/dx(x^2) = 2 x:
H'(x) = 3 - 2 x
Simplify the expression:
Answer: = 3 - 2 x
1. Why is money better than a bartering system?
A People might not have items to trade.
B It helps people to agree on the value of something.
C People might lose track of their money.
D Both A and B
E Both B and C
The correct answer is D. Both A and B
Explanation:
Bartering is an economic system in which products are directly exchanged for other products. For example, a pound of oranges is exchanged for a pound of rice. Due to this, in bartering, there is no money or elements such as coins or bills that represent the value of products or services. This system has both advantages and disadvantages in comparison to the use of money.
In terms of disadvantages, bartering implies individuals need products or services they can use to exchange, which might not be possible for all individuals as not all individuals might produce a product or have a product other are interested in. Also, in bartering the value of products varies, for example, a pound of blueberries can be equal to a pound of rice, three pounds of rice, or even half pound of rice, as values change according to the situation of those participating in the exchange. This means, in bartering the value fluctuates and it is more difficult to agree on the value of something, which does not occur if money is used as each product has a defined price which might just vary slightly. According to this, options A and B are advantages of money over bartering.
Actual time in seconds recorded when statistics students participated in an experiment t test their ability to determine when one minute 60 seconds has passed are shown below.Find the mean median mode of the listed numbers. 53 52 72 61 68 58 47 47
Answer:
53 52 72 61 68 58 47 47 (arrange it)
47 47 52 53 58 61 68 71 (done!)
Mode: 47 (appear twice)
Median: (53+58)/2 = 55.5
Mean = 47+47+52+53+58+61+68+71/ 8
=457/8
=57.12
What is the square root of -1
Answer:
the awnser is sqrt(-1) = i
The price of a technology stock was $ 9.56 yesterday. Today, the price rose to $ 9.69 . Find the percentage increase. Round your answer to the nearest tenth of a percent.
Answer and Step-by-Step explanation:
% increase = 100 x [(new price) - (original price)] / (original price)] = 100 (9.67 - 9.56) / 9.56
% increase ≅ 1.2% (to the nearest tenth)
Solve this problem (-25) +(-12)+(-34)=show me the steps
Answer:
(-25)+(-12)+(-34) = -71
so when you add negative numbers you simply add them such as -2+-2 -4
so same conditions
so it will be -25+-12+-34 and it will simply be 25+12+34 so -71
Please Help
Function 1 is defined by the equation: p=r+7
Function 2 is defined by the table shown in the image below
Which function has a greater slope, function 1 or function 2?
Answer:
The slope of Function 2 (m=1.1) is greater than the slope of Function 1 (m=1).
Step-by-step explanation:
First, note that p is essentially the y and that r is the x. Thus, to make this easier to see, convert p to y and r to x. Thus:
[tex]y=x+7[/tex]
From the above equation, we can determine that the slope is 1. Thus, the slope of Function 1 is 1.
To find the slope of the table, simply use the slope formula. Use any two points. I'm going to use the points (0,8) and (10,19). Let (0,8) be x₁ and y₁, and (10,19) be x₂ and y₂. Therefore:
[tex]m=\frac{y_2-y_1}{x_2-x_1}=\frac{19-8}{10-0}=11/10=1.1[/tex]
Thus, the slope of Function 2 is 1.1.
1.1 is greater than 1.
Thus, the slope of Function 2 is greater than the slope of Function 1.
Answer:
Function 2 has the greater slope
Step-by-step explanation:
Question 18 i will maek the brainliest:)
Answer:
Median: 14.6, Q1: 6.1, Q3: 27.1, IR: 21, outliers: none
Step-by-step explanation:
Step 1: order the data from the least to the largest.
2.8, 3.9, 5.3, 6.1, 6.5, 7.1, 12.5, 14.6, 16.4, 16.4, 20.8, 27.1, 28.1, 30.9, 53.5
Step 2: find the median.
The median is the middle value, which is the 8th value in the data set.
2.8, 3.9, 5.3, 6.1, 6.5, 7.1, 12.5, [14.6,] 16.4, 16.4, 20.8, 27.1, 28.1, 30.9, 53.5
Median = 14.6
Step 2: Find Q1,
Q1 is the middle value of the lower part of the data set that is divided by the median to your left.
2.8, 3.9, 5.3, (6.1), 6.5, 7.1, 12.5, [14.6], 16.4, 16.4, 20.8, 27.1, 28.1, 30.9, 53.5
Q1 = 6.1
Step 3: find Q3.
Q3 is the middle value of the upper part of the given data set.
2.8, 3.9, 5.3, 6.1, 6.5, 7.1, 12.5, [14.6], 16.4, 16.4, 20.8, (27.1), 28.1, 30.9, 53.5
Q3 = 27.1
Step 4: find interquartile range (IR)
IR = Q3 - Q1 = [tex] 27.1 - 6.1 = 21 [/tex]
Step 5: check if there is any outlier.
Formula for checking for outlier = [tex] Q1 - 1.5*IR [/tex]
Then compare the result you get with the given values in the data set. Any value in the data set that is less than the result we get is considered an outlier.
Thus,
[tex] Q1 - 1.5*IR [/tex]
[tex]6.1 - 1.5*21 = -25.4[/tex]
There are no value in the given data set that is less than -25.4. Therefore, there is no outlier.
PLEASE HELP ME I DONT HAVE THAT MANY POINTS AND ITS DUE TODAY I NEED HELP ASAP
The table contains the data for your first weeks sales. Complete the table by calculating your commission and earnings for each day of the week
Answer with explanation:
Sales Commission(10% of sales)
$2,200 0.1×$2,200= $220
$2,000 0.1× $2,000= $200
$3,134 0.1×$3,134=$313.4
$2,417 0.1×$2,417=$241.7
$2,579 0.1×$2,579 =$257.9
The completed table is given as follows
Day Sales Commission Non-Sales pay Earning
(10% of sales) (Commission +Non Sales pay)
Mon $2,200 $220 $9.50 $220+ $9.50=$229.50
Tue $2,000 $200 $9.50 $200 +$9.50=$209.50
Thurs $3,134 $313.4 $9.50 $313.4+ $9.50=$322.9
Fri $2,417 $241.7 $9.50 $241.7+$9.50= $251.2
Sat $2,579 $257.9 $9.50 $257.9+$9.50=$267.4
Need help please will mark brainliest
Step-by-step explanation:
Maximum = 62
Median = (34+37+39+32+48+45+53+62+58+61+60+41)/12= 47.5≈48
quartile
In increasing order
32, 34, 37, 39, 41, 45, 48, 53, 58, 60, 61, 62
Upper quartile= (58+60)/2 = 59
Lower quartile= (37+39)/2 = 38
Minimum= 32
ASAP Which dimensions cannot create a triangle? three angles measuring 10 degrees, 25 degrees, and 145 degrees three sides measuring 9 m, 15 m, and 9 m three angles measuring 40 degrees, 70 degrees, and 65 degrees three sides measuring 6 cm, 8 cm, and 10 cm
Answer:
Three angles measuring 40°, 70° and 65°
Step-by-step explanation:
Because they don't add up to 180°
Answer:
The correct answer is 10° 25° 145°
Step-by-step explanation:
It's because the two smallest angles added up must be greater than the largest angle to create a triangle. Your welcome.
For some postive value of Z, the probability that a standardized normal variable is between 0 and Z is 0.3770. The value of Z is
Answer:
1.16
Step-by-step explanation:
Given that;
For some positive value of Z, the probability that a standardized normal variable is between 0 and Z is 0.3770.
This implies that:
P(0<Z<z) = 0.3770
P(Z < z)-P(Z < 0) = 0.3770
P(Z < z) = 0.3770 + P(Z < 0)
From the standard normal tables , P(Z < 0) =0.5
P(Z < z) = 0.3770 + 0.5
P(Z < z) = 0.877
SO to determine the value of z for which it is equal to 0.877, we look at the
table of standard normal distribution and locate the probability value of 0.8770. we advance to the left until the first column is reached, we see that the value was 1.1. similarly, we did the same in the upward direction until the top row is reached, the value was 0.06. The intersection of the row and column values gives the area to the two tail of z. (i.e 1.1 + 0.06 =1.16)
therefore, P(Z ≤ 1.16 ) = 0.877
A rectangular tank that is 2048 ft cubed with a square base and open top is to be constructed of sheet steel of a given thickness. Find the dimensions of the tank with minimum weight.
Answer:
16ft by 16ft by 8ft.
Step-by-step explanation:
Let the total surface area of the rectangular tank be S = 2LW+2LH+2WH where;
L is the length of the box
W is the width of the box
H is the height of the box.
Since the box is openend at the top, S = lw + 2lh+ 2wh
If the base is a square base then, l = w
S = l(l) + 2wh+2wh
S = l²+4wh ............... 1
If volume = lwh
lwh = 2028 ft³
wh = 2048/l ................ 2
Substitute equation 2 into 1;
S = l²+4(2048/l)
S = l²+8192/l
dS/dl = 2l - 8192/l²
If dS/dl = 0 (since we are looking for dimensions of the tank with minimum weight.)
2l - 8192/l² = 0
2l = 8192/l²
2l³ = 8192
l³ = 8192/2
l³ = 4096
l =∛4096
l = 16 ft
Since the length is equal to the width, hence the width = 16ft (square based tank)
Given the volume V = lwh = 2048
lwh = 2048
16*16*h = 2048
256h = 2048
divide both sides by 256
256h/256 = 2048/256
h = 8ft
Hence, the dimensions of the tank with minimum weight is 16ft by 16ft by 8ft.
Assuming that the loss of ability to recall learned material is a first-order process with a halflife of 35 days. Compute the number of days required to forget 90% of the material that you have learned today. Report to 1 decimal place.
Answer:
5.3 days
Step-by-step explanation:
Let us assume the loss of ability to recall a learned material = 100%
Formula to calculate number of days = time(t) =
t = t½ × Log½(Nt/No)
Nt = Ending Amount
No = Beginning Amount
t½ = Half life
t = Time elapsed
Therefore, we have the following values from the questions:
Half life (t½)= 35 days
Initial or beginning amount = 100%
Ending amount = 90%
t = t½ × Log½ (Nt/No)
t = 35 × Log ½(90/100)
t = 5.3201082705768 days
Approximately = 5.3 days
Find the intervals on which f is increasing and the intervals on which it is decreasing. f(x)=-2cos^(2)x
Answer:
Increasing
0°≤x≤180°
Decreasing
180°≤x≤360°
Solve for x: −3x + 3 −1 b. x −3
Answer:
2/3
Step-by-step explanation:
Your −3x + 3 −1 is not an equation and thus has no solution.
If, on the other hand, you meant
−3x + 3 = 1
then -3x = -2, and x = 2/3
Sean earned 20 points. Charles earned p more points than Sean. Choose the expression that shows how many points Charles earned.
Answer:
the person above is correct if i did this correct
Step-by-step explanation:
According to the local union president, the mean gross income of plumbers in the Salt Lake City area follows a normal distribution with a mean of $48,000 and a population standard deviation of $2,000. A recent investigative reporter for KYAK TV found, for a sample of 49 plumbers, the mean gross income was $47,600. At the 0.05 significance level, is it reasonable to conclude that the mean income is not equal to $47,600? Determine the p value. State the Null and Alternate hypothesis: State the test statistic: State the Decision Rule: Show the calculation: What is the interpretation of the sample data? Show the P value
Answer:
Step-by-step explanation:
Given that:
population mean [tex]\mu[/tex] = 47600
population standard deviation [tex]\sigma[/tex] = 2000
sample size n = 49
Sample mean [tex]\over\ x[/tex] = 48000
Level of significance = 0.05
The null and the alternative hypothesis can be computed as follows;
[tex]H_0 : \mu = 47600 \\ \\ H_1 : \mu \neq 47600[/tex]
Using the table of standard normal distribution, the value of z that corresponds to the two-tailed probability 0.05 is 1.96. Thus, we will reject the null hypothesis if the value of the test statistics is less than -1.96 or more than 1.96.
The test statistics can be calculated by using the formula:
[tex]z= \dfrac{\overline X - \mu }{\dfrac{\sigma}{ \sqrt{n}}}[/tex]
[tex]z= \dfrac{ 48000-47600 }{\dfrac{2000}{ \sqrt{49}}}[/tex]
[tex]z= \dfrac{400 }{\dfrac{2000}{ 7}}[/tex]
[tex]z= 1.4[/tex]
Conclusion:
Since 1.4 is lesser than 1.96 , we fail to reject the null hypothesis and that there is insufficient information to conclude that the mean gross income is not equal to $47600
The P-value is being calculate as follows:
P -value = 2P(Z>1.4)
P -value = 2 (1 - P(Z< 1.4)
P-value = 2 ( 1 - 0.91924)
P -value = 2 (0.08076 )
P -value = 0.16152
Enclosing the Largest Area The owner of the Rancho Grande has 3,052 yd of fencing with which to enclose a rectangular piece of grazing land situated along the straight portion of a river. If fencing is not required along the river, what are the dimensions (in yd) of the largest area he can enclose
Answer:
the shorter side = 1526
the longer side = 763
area = 1164338
Step-by-step explanation:
lets say
a=length
b = width
a + 2b = 3052
this is the perimeter
such that
a = 3052 - 2b
the area of a rectangle is a*b
= (3052 - 2b)b
= 3052b - 2b²
we differentiate this to get:
= 3052 - 4b
such that
3052 = 4b
divide through by 4, to get b, the width
3052/4 = 763
b = 763
put the value of b into a
a = 3052 - 2b
a = 3052 - 2(763)
a = 3052 - 1526
a = 1526
therefore
the shorter side = 1526
the longer side = 763
area = a x b
area = 1526 x 763
area = 1526 x 763
= 1164338
in need of assistance answers are greatly appreciated thank you for your time and effort
Answer:
x = (h+g)/-f
Step-by-step explanation:
-fx-g = h
Add g to each side
-fx-g+g = h+g
-fx = h+g
Divide each side by -f
-fx/-f = (h+g)/-f
x = (h+g)/-f
A recent survey of 1090 U.S. adults selected at random showed that 623 consider the occupation of firefighter to have very great prestige. Estimate the probability (to the nearest hundredth) that a U.S. adult selected at random thinks the occupation of firefighter has very great prestige.
Answer:
0.572
Step-by-step explanation:
From the question,
We have
n = 1090 of US adults
x = 623 selected from this population at random who consider the occupation to be one of great prestige
So we have that
The probability of X = x/n
= 623/1090
= 0.572
We conclude that 0.572 is the probability that a US adult selected at random thinks the occupation has great prestige.
In a triangle ABC two points D,E are taken on BC so that angle BAD=angle DAE=angleCAE. Determine AE if AB=5,BC=10 angle BAC=90. PLEASE HELP I NEED HELP WITHIN TEN MINS PLEASE
Answer:
AE = 7.5
Step-by-step explanation:
Since <BAC = [tex]90^{0}[/tex], then;
<BAD = <DAE = <CAE = [tex]30^{0}[/tex] (complementary angles)
From ΔABC, applying the Pythagoras theorem to determine the length of side AC;
[tex]/BC/^{2}[/tex] = [tex]/AC/^{2}[/tex] + [tex]/AB/^{2}[/tex]
[tex]/10/^{2}[/tex] = [tex]/AC/^{2}[/tex] + [tex]/5/^{2}[/tex]
100 = [tex]/AC/^{2}[/tex] + 25
[tex]/AC/^{2}[/tex] = 100 - 25
[tex]/AC/^{2}[/tex] = 75
AC = [tex]\sqrt{75}[/tex]
Applying trigonometric function to ΔCAE,
Cos [tex]30^{0}[/tex] = [tex]\frac{AE}{\sqrt{75} }[/tex]
AE = [tex]\sqrt{75}[/tex] × Cos [tex]30^{0}[/tex]
= 7.5
Therefore, AE = 7.5
What is the simplified form of the following expression? 2 StartRoot 18 EndRoot + 3 StartRoot 2 EndRoot + StartRoot 162 EndRoot
Answer: 2*√18 + 3*√2 + √162 = 18*√2
Step-by-step explanation:
I guess that the equation is:
2*√18 + 3*√2 + √162
And we want to simplify it.
first 18 = 9*2
then we can write:
2*√18 = 2*√(9*2) = 2*3*√2 = 6*√2
and 162/9 = 18
then we can write:
√162 = √(9*18) = √9*√18 = 3√18
now we can use the previous step: √18 = 3*√2
and:
√162 = 3*(3*√2) = 9*√2
now we can write our equation as:
6√2 + 3√2 + 9√2 = (6 + 3 + 9)√2 = 18*√2
And now we can not simplify it further more, so here we end.
Answer:
B. 18 sqrt 2
Step-by-step explanation:
This is the correct letter and answer on edge, if thats what youre using:)
what is the number if 4 is subtracted from the sum of one fourth of 5 times of 8 and 10
Answer:
Step-by-step explanation:
Lets, turn this into words and use order of operations, First, we look for multiplication and division.
the sum of one fourth of 5 times of 8 and 10 gets you 1/4(5*8) + 10 = 20
what is the number if 4 is subtracted from the sum
20 - 4 = 16
What is the simplified form of x minus 5 over x squared minus 3x minus 10⋅ x plus 2 over x squared plus x minus 12 ? (6 points) Select one: a. 1 over the quantity x minus 3 times the quantity x plus 4 b. 1 over the quantity x minus 3 times the quantity x plus 2 c. 1 over the quantity x plus 4 times the quantity x minus 5 d. 1 over the quantity x plus 2 times the quantity x minus 5
Answer:
[tex]\ \text{a. }\quad\dfrac{1}{(x-3)(x+4)}[/tex]
Step-by-step explanation:
Maybe you want the product ...
[tex]\dfrac{x-5}{x^2-3x-10}\cdot\dfrac{x+2}{x^2+x-12}=\dfrac{x-5}{(x-5)(x+2)}\cdot\dfrac{x+2}{(x-3)(x+4)}\\\\=\boxed{\dfrac{1}{(x-3)(x+4)}}[/tex]
__
Numerator factors of (x-5) and (x+2) cancel those in the denominator.
Find the inverse of the following function.
Answer:
The inverse is 1/64 x^2 = y x ≥ 0
Step-by-step explanation:
f(x) = 8 sqrt(x)
y = 8 sqrt(x)
Exchange x and y
x = 8 sqrt (y)
Solve for y
Divide each side by 8
1/8 x = sqrt(y)
Square each side
(1/8 x)^2 = (sqrt(y))^2
1/64 x^2 = y
The inverse is 1/64 x^2 = y x ≥ 0
since x ≥0 in the original function
Answer:
[tex]\Huge \boxed{\mathrm{D}}[/tex]
Step-by-step explanation:
[tex]f(x)=8\sqrt{x}[/tex]
[tex]\sf Replace \ with \ y.[/tex]
[tex]y=8\sqrt{x}[/tex]
[tex]\sf Switch \ the \ variables.[/tex]
[tex]x= 8\sqrt{y}[/tex]
[tex]\sf Divide \ both \ sides \ of \ the \ equation \ by \ 8.[/tex]
[tex]\displaystyle \frac{x}{8} =\sqrt{y}[/tex]
[tex]\sf Square \ both \ sides \ of \ the \ equation.[/tex]
[tex]\displaystyle (\frac{x}{8} )^2 =y[/tex]
[tex]\displaystyle \frac{x^2 }{64} =y[/tex]
[tex]\displaystyle f^{-1}(x)=\frac{1}{64} x^2[/tex]
Which of the following is NOT a requirement of testing a claim about two population means when 1 and 2 are unknown and not assumed to be equal? Choose the correct answer below. A. The two samples are dependent. B. Both samples are simple random samples. C. Either the two sample sizes are large (30 and 30) or both samples come from populations having normal distributions, or both of these conditions are satisfied. D. The two samples are independent.
Answer:
b
Step-by-step explanation:
Question
The point (-2,r) lies on the graph of 2x + y = 7 in the xy-plane. What is the value of r?
Answer: r = 11
Step-by-step explanation:
We know that the point (-2, r) lies on the graph of:
2*x + y = 7.
Then, if we that point is on the graph of the equation, we can replace the values and we will have:
2*(-2) + r = 7
and now we solve this for r-
-4 + r = 7
r = 7 + 4 = 11
r = 11
