2.7.2 : Checkup - Practice Problems

Answer:

[tex]x = \sqrt{-2} = 2i[/tex]

Step-by-step explanation:

[tex]5x^2-2=-12[/tex]

[tex]5x^2 =-10[/tex]

[tex]x^2 =-2[/tex]

[tex]x = \sqrt{-2} = 2i[/tex]

Answer:

$3.22 per square feet

Step-by-step explanation:

To solve, I usually set up an equation:

sq ft  = 12 1/2 = 1

 $        40.21     x

Then, use cross multiplication.

(12 1/2)x=40.21

Divide both sides by 12 1/2 or 12.5

x = 3.2168

Round to the hundredths place [because we're dealing with money]

$3.22

I hope this helps!

Answer:

3.22 per sq ft

Step-by-step explanation:

Take the total cost and divide by the amount of tiles

40.21 / 12.5

3.2168 per sq ft

Rounding to the nearest cent

3.22 per sq ft

Answer:

The price of 1 exercise book is $122.45.

Step-by-step explanation:

This question is solved using a system of equations.

I am going to say that:

x is the price of one exercise book.

y is the price of one textbook.

Total cost of 10 exercise books and 2 textbooks is $1400.00.

This means that:

[tex]10x + 2y = 1400[/tex]

Since we want x:

[tex]2y = 1400 - 10x[/tex]

[tex]y = 700 - 5x[/tex]

One also finds the total cost of 3 textbooks and 30 exercise books is $3000.

This means that:

[tex]3x + 30y = 3000[/tex]

Since [tex]y = 700 - 5x[/tex]

[tex]3x + 30(700 - 5x) = 3000[/tex]

[tex]3x + 21000 - 150x = 3000[/tex]

[tex]147x = 18000[/tex]

[tex]x = \frac{18000}{147}[/tex]

[tex]x = 122.45[/tex]

The price of 1 exercise book is $122.45.

Answer:

5000 km

Step-by-step explanation:

We are given that

3 cm represents on a map of  a town=150 m

Distance between two points=1 km

We have to find the distance between two points on the map.

3 cm represents on a map of  a town=150 m

1 cm represents on a map of  a town=150/3 m

1 km=1000 m

1 m=100 cm

[tex]1km=1000\times 100=100000 cm[/tex]

100000 cm  represents on a map of  a town

=[tex]\frac{150}{3}\times 100000[/tex] m

100000 cm  represents on a map of  a town=5000000 m

100000 cm  represents on a map of  a town

=[tex]\frac{5000000}{1000} km[/tex]

100000 cm  represents on a map of  a town=5000 km

Hence, two points are separated by 5000 km on the map.

Answer:

you have to wait until two people answer then you click their answer to make them brainliest

Step-by-step explanation:

i dont know

blah blah blah blah blah blah blah blah blah blah blah blah

Answer:

By these examples you are able to see that the square of an odd number is always 1 more than a multiple of 4.

Step-by-step explanation:

For examples,

Let's consider squares of 3, 11, 25, 37 and 131.

[tex] {3}^{2} = 9[/tex]

8 is a multiple of 4, and 9 is more than 8.

[tex] {11}^{2} = 121[/tex]

120 is a multiple of 4 and 121 is one more than it.

[tex] {25}^{2} = 625[/tex]

624 is a multiple of 4 and 625 is one more than it.

[tex] {37}^{2} = 1369[/tex]

1368 is a multiple of 4 and 1369 is one more than 1368.

[tex] {131}^{2} = 17161[/tex]

17160 is a multiple of 4.

Answer

500,000 + 500,000 = 1,000,000

Step-by-step explanation:

Answer:

Terms:

Like Terms:

Coefficients:

Constants:

You simplify the expression by combining like terms:

-5x + 4 - x - 1 = -6x + 5

(7b - 4) + (-2b + a + 1) = 7b - 4 - 2b + a + 1 = 5b + a - 3

Answer:

6x + y

Step-by-step explanation:

6x + 3y/3​

6x + y

Answer:

6x + y

Step-by-step explanation:

6x + 3y / 3

cancel 3y by 3

6x + y

Answer:

Hello dude

[tex] - 1 \frac{21}{24} + 1 \frac{22}{24} = + \frac{1}{24} [/tex]

so it's positive

HAVE A NİCE DAY

Step-by-step explanation:

GREETİNGS FROM TURKEY ツ

Answer - It’s 31.56

Step-by-step explanation: You just do regular multiplication and then add  the decimal point

Answer:

Function has a minimum value

So, f(x)=0 and f(4)=-3

f(4)=-3 and f(x)=-x+4

f(4)=0

OAmalOHopeO

Answer:

x = 2

Step-by-step explanation:

The minimum point of the curve is (2, 0). Hence, axis of symmetry is x = 2

Answer:

[tex]-\dfrac{2}{17} + \dfrac{9}{17}i[/tex]

Step-by-step explanation:

[tex] (2 + i) \div (1 - 4i) = [/tex]

[tex] = \dfrac{2 + i}{1 - 4i} [/tex]

[tex] = \dfrac{2 + i}{1 - 4i} \times \dfrac{1 + 4i}{1 + 4i} [/tex]

[tex] = \dfrac{(2 + i)(1 + 4i)}{(1 - 4i)(1 + 4i)} [/tex]

[tex] = \dfrac{2 + 8i + i + 4i^2}{1 + 16} [/tex]

[tex] = \dfrac{2 + 9i - 4}{17} [/tex]

[tex] = \dfrac{-2 + 9i}{17} [/tex]

[tex]= -\dfrac{2}{17} + \dfrac{9}{17}i[/tex]

9514 1404 393

Answer:

  ∠CAB = 86°

  ∠ABC = 43°

  ∠BCA = 51°

Step-by-step explanation:

This can be done a couple of different ways (as with most math problems). We can use the distance formula to find the side lengths, then the law of cosines to find the angles. Or, we could use the dot product. In the end, the math is about the same.

The lengths of the sides are given by the distance formula.

  AB² = (4-1)² +(-3-0)² +(0-(-1)) = 16 +9 +1 = 26

  BC² = (1-4)² +(2-(-3))³ +(3-0)² = 9 +25 +9 = 43

  CA² = (1-1)² +(0-2)² +(-1-3)² = 4 +16 = 20

From the law of cosines, ...

  ∠A = arccos((AB² +CA² -BC²)/(2·AB·CA)) = arccos((26 +20 -43)/(2√(26·20)))

  ∠A = arccos(3/(4√130)) ≈ 86°

  ∠B = arccos((AB² +BC² -AC²)/(2·AB·BC)) = arccos((26 +43 -20)/(2√(26·43)))

  ∠B = arccos(49/(2√1118)) ≈ 43°

  ∠C = arccos((BC² +CA² -AB²)/(2·BC·CA)) = arccos((43 +20 -26)/(2√(43·20)))

  ∠C = arccos(37/(4√215)) ≈ 51°

The three angles are ...

  ∠CAB = 86°

  ∠ABC = 43°

  ∠BCA = 51°

_____

Additional comment

This sort of repetitive arithmetic is nicely done by a spreadsheet.

Answer:

0.3573 = 35.7%

Step-by-step explanation:

We roll a pair of dice 10,000 times so the mean and standard deviation is,

μ  = 10000/36  =277.7          σ = [tex]\sqrt{10000*\frac{35}{36^{2} } } =16.4[/tex]

[tex]z_{1}[/tex] = (280 - 277.7)/16.4 = .14

[tex]z_{2}[/tex] = (300 - 277.7)/16.4 = 1.35

Probablity (range)  

0.3573  

Z(low)=0.14        0.555766357

Z(upper)=1.36        0.91304644

Answer:

9x² - 4/3x + ¼

Step-by-step explanation:

(3x - ½)²

(3x - ½)(3x -½)

9x² - ⅔x - ⅔x + ¼

9x² - 4/3x + ¼

Answer:

Lf(x) = Lg(x) = Lh(x) =  1 - 2x

value of the functions and their derivative are the same at x = 0

Step-by-step explanation:

Given :

f(x) = (x − 1)^2,  

g(x) = e^−2x ,  

h(x) = 1 + ln(1 − 2x).

a) Determine Linearization of  f, g and h  at a = 0

L(x) = f (a) + f'(a) (x-a)  ( linearization of f at a )

for f(x) = (x − 1)^2  

f'(x ) = 2( x - 1 )

at x = 0

f' = -2  

hence the Linearization at a = 0

Lf (x) = f(0) + f'(0) ( x - 0 )

Lf (x) = 1 -2 ( x - 0 ) = 1 - 2x

For g(x) = e^−2x

g'(x) = -2e^-2x

at x = 0

g(0) = 1

g'(0) = -2e^0 = -2

hence linearization at a = 0

Lg(x) = g ( 0 ) + g' (0) (x - 0 )

Lg(x) = 1 - 2x

For h(x) = 1 + ln(1 − 2x).

h'(x) =  -2 / ( 1 - 2x )

at x = 0

h(0) = 1

h'(0) = -2

hence linearization at a = 0

Lh(x) = h(0) + h'(0) (x-0)

        = 1 - 2x

Observation and reason

The Linearization is the same in every function i.e. Lf(x) = Lg(x) = Lh(x) this is because the value of the functions and their derivative are the same at x = 0

Answer:

1.a+4=11

a=7

2.6=g+8

g=2

3.

?

4.k+8=3

k=-5

5.j+0=9

j=9

6.12+y=15

y=3

7.h-4=0

h=4

8.m-7=1

m=8

9.w+5=4

w=-2

10.b-28=33

b=61

11.45+f=48

f=3

12.n+7.1=8.6

n=1.5

Hope This Helps!!!

Answer:

A. ¼

Step-by-step explanation:

Rate of change (m) = [tex] \frac{y_2 - y_1}{x_2 - x_1} [/tex]

Using two points on the line, (4, 1) and (-4, -1), find the rate of change using the formula stated above:

Where,

[tex] (4, 1) = (x_1, y_1) [/tex]

[tex] (-4, -1) = (x_2, y_2) [/tex]

Plug in the values

Rate of change (m) = [tex] \frac{-1 - 1}{-4 - 4} [/tex]

= [tex] \frac{-2}{-8} [/tex]

= [tex] \frac{1}{4} [/tex]

Rate of change = ¼

Answer:

20

Step-by-step explanation:

y=kx

24=6k

k=4

y=4*5=20

Answer:

The length of MN is 4

Choose B

Step-by-step explanation:

You would multiply 4 and 3, and 2 and 9 separately, then add them, then subtract 40. Remember PEMDAS.

(4*3) + (2*9) - 40

12 + 18 - 40

-10

Hope that helps

Answer:

B

Step-by-step explanation:

When we reflect something across the y axis, the y axis stays the same but the x values change by a factor of -1.

B is the Answer

Answer:

c. switch the x-values and y-values in the table

Step-by-step explanation:

For any table or graph reflection over the line y=x

The rule is (x,y) ----> (y,x)

f(x) is reflected over the line y=x, so the coordinates of f(x) becomes

(-2,-31) becomes (-31,-2)

(-1,0) becomes (0,-1)

(1,2) becomes (2,1)

(2,33) becomes (33,2)

As per the rule, we switch the x-values and y-values in the table

For reflection over the line y=x , the coordinate becomes

(-31,-2)

(0,-1)

(2,1)

(33,2)

Answer:

the operating characteristics have been solved below

Step-by-step explanation:

we have an average of 10 minutes per customers

μ = mean service rate = 60/10 = 6 customers in one hr

the average number of customers that are waiting in line

mean arrival λ = 2.5

μ = 6

[tex]Lq = \frac{2.5^{2} }{6(6-2.5)} \\[/tex]

= 6.25/21

= 0.2976

we calculate the average number of customers that are in the system

[tex]L=Lq+\frac{2.5}{6}[/tex]

= 0.2976+0.4167

= 0.7143

we find the average time that a customer spends in waiting

[tex]Wq=\frac{0.2976}{2.5}[/tex]

= 0.1190 hours

when converted to minutes = 0.1190*60 = 7.1424 minutes

[tex]0.1190+\frac{1}{6}[/tex]

=0.2857

probability that arriving customers would wait for the service

= 2.5÷6 = 0.4167

Answer:

The difference is that Marla's exam in her statistics class was graded by percent of correct answers, in her case 70%, while the SAT is graded into a curve, taking other students' grades also into account, and since she scored in the 70th percentile, Marla scored better than 70% of the students.

Step-by-step explanation:

Marla scored 70% on her last unit exam in her statistics class.

This means that in her statistics class, Marla got 70% of her test correct.

When Marla took the SAT exam, she scored at the 70th percentile in mathematics.

This means that on the SAT exam, graded on a curve, Marla scored better than 70% of the students.

Explain the difference in these two scores.

The difference is that Marla's exam in her statistics class was graded by percent of correct answers, in her case 70%, while the SAT is graded into a curve, taking other students' grades also into account, and since she scored in the 70th percentile, Marla scored better than 70% of the students.

Answer:

(0.8165 ; 0.8819)

Lower boundary = 0.8165

Upper boundary = 0.8819

Step-by-step explanation:

Given :

Sample proportion. Phat = x/ n = 276/ 325 = 0.8492

Confidence interval :

Phat ± margin of error

Margin of Error = Zα/2* [√Phat(1 - Phat) / n]

Phat ± Zα/2* [√Phat(1 - Phat) / n]

The 90% Z critical value is = 1.645

0.8492 ± 1.645*[√0.8492(1 - 0.8492) / 325)

0.8492 ± 1.645*[√0.8492(0.1508) / 325]

0.8492 ± 1.645*√0.0003940288

0.8492 ± 0.0326535

Lower boundary = 0.8492 - 0.0326535 = 0.8165

Upper boundary = 0.8492 + 0.0326535 = 0.8819

Confidence interval = (0.8165 ; 0.8819)

Answer:

2x + y

Step-by-step explanation:

x² + xy - y² = 4

→ Remember the rule, bring the power down then minus 1

2x + y

Answer:

2 < x < 6

Step-by-step explanation:

x/10

1/5 = 2/10

.6 = 6/10

2 < x < 6