resolver la siguiente ecuación por eliminación o sustitución: a-8b= -9 a-2b= -7

Answers

Answer 1

Answer: Solution: [tex]a=\dfrac{-19}{3}[/tex] and [tex]b=\dfrac{1}{3}[/tex] .

Step-by-step explanation:

The given pair of equations:

[tex]a-8b= -9\ ...(i)\\\\ a-2b= -7\ ...(ii)[/tex]

Eliminate equation (i) from (ii) , we get

[tex]-2b-(-8b)=-7-(-9)\\\\\Rightarrow\ -2b+8b=-7+9\\\\\Rightarrow\ 6b=2\\\\\Rightarrow\ b=\dfrac{1}{3}[/tex]

Put value of b in (ii) , we get

[tex]a-2\times\dfrac{1}{3}=-7\\\\\Rightarrow\ a=-7+\dfrac{2}{3}\\\\\Rightarrow\ a=\dfrac{-21+2}{3}\\\\\Rightarrow\ a=\dfrac{-19}{3}[/tex]

Solution: [tex]a=\dfrac{-19}{3}[/tex] and [tex]b=\dfrac{1}{3}[/tex] .


Related Questions

On a number line if point A lies -3 and point B lies on 4, what is the length of AB

Answers

Answer:

7

Step-by-step explanation:

4-(-3)=

4+3=

7

Answer:

7

Step-by-step explanation: take the absolute value of both numbers and add them together so -3 becomes 3 and 4 stays the same they add up to 7.

A VERTICAL POLE OF CAST A SHADOW OF 4.5m LONG AT THE SAME TIME A TREE OF HEIGHT 24m LONG CAST A SHADOW OF 6m LONG. FIND THE HEIGHT OF THE POLE.​

Answers

Answer:

18 metres

Step-by-step explanation:

4.5/6 = x/24

¾= x/24

x = 18 m

help me please ;))) (yes im very rich that's why I'm giving out lots of points -_- (and brainly ;))

Answers

Answer:

(I) 17.25 miles

(ii) 1hr56mins20seconds

(III) 4hrs47mins38seconds

Step-by-step explanation:

(I) read from the lowest distance given

(ii) read from the longest time given

(III) added all times together to get total cycling time

Step-by-step explanation:

here,

shortest distance is 17.25 miles

the longest time is 1:56:20 hrs:mins:secs

total time is 4:47:38

Convert 25 feet per second to miles per hour.​

Answers

1 mile = 5,280 feet

1 hour = 3600 seconds

3600/5280 = 0.681818 feet per second

25 ft per second x 0.681818 = 17.045 miles per hour

Round the answer as needed.

Answer:

The correct answer is 17.045 miles per hour.

On Thursday, 40 trains left the station. Eight left late. On Saturday 50 trains left the station. Nine left late. What percentage of trains were not late on each day?

Answers

Answer:

Thursday=80%

Saturday=82 %

Step-by-step explanation:

Thursday trains not late=40-8=32

% trains not late=32/40×100=80

Saturday trains not late=50-9=41

% trains not late on Saturday=41/50×100=82

The mean amount purchased by a typical customer at Churchill's Grocery Store is $23.50 with a standard deviation of $5.00. Assume the distribution of amounts purchased follows the normal distribution. For a sample of 50 customers, answer the following questions.
(a) What is the likelihood the sample mean is at least $25.00? (Round z value to 2 decimal places and final answer to 4 decimal places.)
Probability
(b) What is the likelihood the sample mean is greater than $22.50 but less than $25.00? (Round z value to 2 decimal places and final answer to 4 decimal places.)
Probability
(c) Within what limits will 90 percent of the sample means occur? (Round your answers to 2 decimal places.)

Answers

Answer:

a. [tex]\mathtt{P(X \geq 25) =0.0170}[/tex]     ( to four decimal places)

b. [tex]P(22.5<X<25) = 0.9043[/tex]   ( to four decimal places )

c. The limits will be between the interval of   ( 22.33,24.67 )

Step-by-step explanation:

Given that :

mean = 23.50

standard deviation = 5.00

sample size = 50

The objective is to calculate the following:

(a)  What is the likelihood the sample mean is at least $25.00?

Let X be the random variable, the probability that the sample mean is at least 25.00 is:

[tex]P(X \geq 25) = 1 - P(\dfrac{X - \mu}{\dfrac{\sigma}{\sqrt{n}}} < \dfrac{25- 23.50}{ \dfrac{5}{\sqrt{ 50}} })[/tex]

[tex]P(X \geq 25) = 1 - P(Z< \dfrac{1.5}{ \dfrac{5}{7.07107}} })[/tex]

[tex]P(X \geq 25) = 1 - P(Z< \dfrac{1.5 \times 7.071}{ {5}})[/tex]

[tex]P(X \geq 25) = 1 - P(Z< 2.1213)[/tex]

[tex]P(X \geq 25) = 1 - P(Z< 2.12)[/tex]   to two decimal places

From the normal tables :

[tex]P(X \geq 25) = 1 - 0.9830[/tex]

[tex]\mathtt{P(X \geq 25) =0.0170}[/tex]     ( to four decimal places)

(b) What is the likelihood the sample mean is greater than $22.50 but less than $25.00?

[tex]P(22.5<X<25) = P(\dfrac{X-\mu}{\dfrac{\sigma}{\sqrt{n}}} <\dfrac{25-23.5}{\dfrac{5}{\sqrt{50}}} ) - P(\dfrac{X-\mu}{\dfrac{\sigma}{\sqrt{n}}} <\dfrac{22.5-23.5}{\dfrac{5}{\sqrt{50}}} )[/tex]

[tex]P(22.5<X<25) = P(Z<\dfrac{1.5}{\dfrac{5}{7.071}} ) - P(Z<\dfrac{-1}{\dfrac{5}{7.071}} )[/tex]

[tex]P(22.5<X<25) = P(Z<2.12) - (Z<-1.41 )[/tex]

[tex]P(22.5<X<25) = (0.9830 ) - (0.0787)[/tex]

[tex]P(22.5<X<25) = 0.9043[/tex]  to four decimal places

(c) Within what limits will 90 percent of the sample means occur?

At 90 % confidence interval, level of significance = 1 - 0.90 = 0.10

The critical value for the [tex]z_{\alpha/2} = 0.05[/tex] = 1.65

Standard Error = [tex]\dfrac{\sigma}{\sqrt{n}}[/tex]

Standard Error =  [tex]\dfrac{5}{\sqrt{50}}[/tex]

Standard Error = 0.7071

Therefore, at 90 percent of the sample means, the limits will be between the intervals of : [tex](\mu \pm z_{\alpha/2} \times S.E)[/tex]

Lower limit =  ( 23.5 - (1.65×0.707) )

Lower limit =  ( 23.5 - 1.16655 )

Lower limit = 22.33345

Lower limit = 22.33    (to two decimal places).

Upper Limit = ( 23.5 + (1.65*0.707) )

Upper Limit = ( 23.5 + 1.16655 )

Upper Limit = 24.66655

Upper Limit = 24.67

The limits will be between the interval of   ( 22.33,24.67 )

PLEASE help me solve this question! No nonsense answers please!

Answers

Answer:

10x -24 ft^2

Step-by-step explanation:

The area of the square is x^2

The area of the flower garden is lw

( x-4) ( x-6)

x^2 -6x-4x +24

x^2 -10x +24

Subtract the flower garden from the square to find the area of the patio

x^2 - ( x^2 -10x +24)

Distribute the minus sign

x^2 -x^2 +10x -24

10x -24

Answer:

c. 10x -24 sq. ft

Step-by-step explanation:

area of lot = x * x

area of garden = (x-4)(x-6) = x^2-10x+24

Area of patio

= area of lot - area of patio

= x^2 -(x^2-10x+24)

= 10x-24 sq.ft

8(4k - 4) = -5k - 32

Answers

Answer:

k=0

Step-by-step explanation:

8(4k-4)=5k-32

32k-32=-5k-32

32k-32+32=-5k-32+32

32k=-5k

32k+5k=-5k+5k

37k=0

37k/37=0/37

k=0

Answer:

k=0

Step-by-step explanation:

To solve for k, we need to first distribute the 8 through the parenthesis.

32k-32=-5k-32

Lets add 5k to both sides.

37k-32=-32

add 32 to both sides

37k=0

divide 37 from both sides

k=0

I need help with five math questions please help

Answers

Answer:

-5X+2Y-2

Step-by-step explanation:

-5X-7-2+2Y+7

-5X-2+2Y

HOPE I HELPED

PLS MARK BRAINLIEST

DESPERATELY TRYING TO LEVEL UP

✌ -ZYLYNN JADE ARDENNE

JUST A RANDOM GIRL WANTING TO HELP PEOPLE!

                               PEACE!

Fachorise completely
x^2y^2-1​

Answers

Answer:

[tex](xy+1)(xy-1)[/tex]

Step-by-step explanation:

x²y²-1

=(xy)²-(1)²

=(xy+1)(xy-1)

What are all the numbers of Pi? I need this now please

Thank you!! ♥︎

Answers

Answer:

3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679 ...

Step-by-step explanation:

If two angles are complements of each other then each angle is

Answers

Answer:

each angle is less than 90 degrees. angle 1+angle2=90 degrees

Step-by-step explanation:

Which polynomial is a factor of both expressions? x – 8 x + 7 x – 2 (x – 2)2

Answers

Answer:

C. x-2

Step-by-step explanation:

edge

Answer: the 3rd the answer c

x-2

Step-by-step explanation:

how many are 9 raised to 3 ???​

Answers

Answer:

[tex]\huge \boxed{729}[/tex]

Step-by-step explanation:

9 raised to 3 is the base 9 with an exponent of 3.

[tex]9^3[/tex]

9 is being multiplied by itself 3 times.

[tex]9^3 =9 \times 9 \times 9 = 729[/tex]

Solve the equation for x. the square root of the quantity x plus 4 end quantity minus 7 equals 1

Answers

Answer:

x = 60

Step-by-step explanation:

I hope it helps :)

[tex]\sqrt{x+4} -7=1\\\mathrm{Add\:}7\mathrm{\:to\:both\:sides}\\\sqrt{x+4}-7+7=1+7\\\sqrt{x+4}=8\\\mathrm{Square\:both\:sides}\\\left(\sqrt{x+4}\right)^2=8^2\\x+4=64\\x = 64-4\\x = 60[/tex]

There are 4 colas, 1 ginger, 7 root beers, and 6 cherry sodas in a cooler. What are the odds of choosing a ginger ale? Give your answer in a proportion in lower terms.

Answers

Answer:

Step-by-step explanation:

the odds of choosing a ginger ale is 1/21

The odds of choosing a ginger ale is 1/18.

To find the proportion, add all the numbers together, and put that as the denominator. Put the number that you are trying to find the proportion of as the numerator

Samuel has $20 in his savings account before he makes a deposit of $160 after two weeks he withdraws $160 how did Samuel savings account balance change

Answers

Samuel’s saving account changed from 20 to 180 to back to 20


The table below shows the number of cars Jing sold each month last year.
What is the median of the data in the table.
13
16
19
20.5
23.5
Other:

Answers

Answer:

The median of the data in the table is 19.

Step-by-step explanation:

We are given the following data that shows the number of cars Jing sold each month last year below;

Number of cars Jing sold: 13, 16, 19, 20.5, 23.5

For calculating the median, firstly we have to observe that the number of observations (n) in our data is even or odd because;

If n is odd, then the formula for calculating median is given by;

                           Median = [tex](\frac{n+1}{2} )^{th} \text{ obs.}[/tex]

If n is even, then the formula for calculating median is given by;

                           Median = [tex]\frac{(\frac{n}{2} )^{th} \text{ obs.} + (\frac{n}{2}+1 )^{th} \text{ obs.} }{2}[/tex]

Here, the number of observations in our data is odd, i.e. n = 5.

So, Median = [tex](\frac{n+1}{2} )^{th} \text{ obs.}[/tex]

                   = [tex](\frac{5+1}{2} )^{th} \text{ obs.}[/tex]

                   = [tex](\frac{6}{2} )^{th} \text{ obs.}[/tex]

                   = 3rd obs. = 19

Hence, the median of the data in the table is 19.

Please solve these questions on the topic of exponents

Answers

Answer/Step-by-step explanation:

Recall: [tex] x^{-a} = \frac{1}{x^a} [/tex]

a. [tex] 4^{-3} = \frac{1}{4^3} = \frac{1}{64} [/tex]

b. [tex] 13^{-2} = \frac{1}{13^2} = \frac{1}{169} [/tex]

c. [tex] (-3)^{-2} = \frac{1}{-3^2} = \frac{1}{9} [/tex]

how many terms are there in the expressions 1 + 2k - j

Answers

Answer:

3 terms

Step-by-step explanation:

A term in mathematics, especially in Algebra, could be a number, a variable, variable together with a number or variables multiplied together as a single whole. Terms are usually separated with either negative or positive sign in an expression.

In the expression, [tex] 1 + 2k - j [/tex] , there are 3 terms here spared by either the negative sign or the positive.

The 3 terms are: [tex] 1, 2k, j [/tex].

PLEASE ANSWER QUICKLY ASAP
COMPLETE QUESTION B​

Answers

Answer:

Sector

Step-by-step explanation:

A sector of a circle is the portion of circle enclosed by two radii and arc

the first four terms of the sequence an=2n+3are
answer
5,8,11,14
3,5,7,9
1,3,5,7
5,7,9,11​

Answers

Step-by-step explanation:

Hey, there!!!

Your required answer is optionD.

checking,

The 1st sequences are,

5,8,11,14

here,

now, use formula,

(an = 2n+3) in the sequences,

a1 = 2×1+3=5 = matching

a2= 2×2+3=7 = not matched

a3= 2×3+3= 9 = not matched

a4= 2×4+3=11 = not matched.

For 2nd sequences

3,5,7,9

Use the formula of an term,

a1 = 2×1+3=5 = not matched

a2 =2×2+3=7not matched

a3 = 2×3+3=9= not matched.

For 3rd sequences,

1,3,5,7

a1=2×1+3=5= not matched

a2=2×2+3=7= not matched

a3=2×3+3=9= not matched

a4=2×4+3=11= not matched

Now, for 4th sequences,

5,79,11

a1=2×1+3=5= matching

a2=2×2+3=7= matching

a3= 2×3+3=9= matching

a4=2×4+4=11= matching

Therefore, the answer is option D.

Hope it helps..

A student uses his place value chart to show number after the teacher instructed him to divide a number by 100 the charge of 28.003 what was the chart look like first

Answers

Step-by-step explanation:

A student divided the given number by 100 that resulted to 28.003 in his chart. So what we are looking for in the given situation is that the value of the number before it was divided by 100.

To get the desired value, we can simply multiply the obtained result by 100

=> 28.003 x 100

=> 2800.3

So, by dividing 100 to the given number, we simply move the value to the right in a value of hundreds.

Find the term of each sequence.

32, 80, 200, ...5th term

Answers

Answer:

t5 = 1250

Step-by-step explanation:

Each term is derived by multiplying the previous term by 2.5

t2 = t1 * 2.5

t2 = 32 * 2.5

t2 = 80

===========

tn = a*b^(n - 1)

t3 = 32*2.5^2

t3 = 200

That's just to test the formula. It does work.

===============

t5 = 32*2.5^(5 -1)

t5 = 32*2.5^4

t5 = 1250

A certain mixture of paint contains 5 parts white paint for every 4 parts blue paint. If a can of paint contains 75 ounces of white paint, how many ounces of blue paint are in the can?

Answers

Answer:

60 ounces.

Step-by-step explanation:

Given:

A mixture contains 5 parts of white paint for every 4 parts of blue paint.

i.e. Ratio of white paint : blue paint = 5 : 4

Quantity of White paint = 75 ounces

To find:

How many ounces of blue paint = ?

Solution:

Here, we are given the ratio of white and blue paint in the mixture.

Also, we are given the quantity of white paint in the paint can.

And we have to find the quantity of other paint in the can.

Let us use all the given statements to find the unknown quantity of blue paint.

Ratio of white paint : blue paint= Ratio of quantity of white paint: blue paint

[tex]\dfrac{5}{4} = \dfrac{75}{\text{Quantity of blue paint}}\\\Rightarrow \text{Quantity of blue paint} = 15 \times 4\\\Rightarrow \text{Quantity of blue paint} = 60\ ounces[/tex]

So, the quantity of blue paint in the can is 60 ounces.

1 1/3 minus 5/6 please help me out

Answers

Answer:

17/6

So this is the answer. If you want to convert to decimal... The answer will be 2.83..hope it is right

We can calculate E, the amount of euros that has the same value as D U.S. dollars, using the equation e=17/20d. How many U.S. dollars have the same value as 1 euro?

Answers

Answer:

1.18 dollar.

Step-by-step explanation:

E = 17/20D

E => The amount in euros.

D => The amount in dollars.

From the question given,

E = 1

D =?

E = 17/20D

1 = 17/20D

Cross multiply

20 x 1 = 17D

20 = 17D

Divide both side by 17

D = 20/17

D = 1.18

Therefore, 1.18 dollar is equivalent to 1 euro.

Answer:

How many Euros have the same value as 1 U.S. dollar?

17/20 euros

How many U.S. dollars have the same value as 1 euro?

59/50 dollars

(or 0.85 either one is correct)

Step-by-step explanation:

Khan Academy

Hope this helps! ;)

What is the distance between the points (5,1) and (-3,-5)?

Answers

Answer

[tex] \boxed{10 \: \: units}[/tex]

Step by step explanation

Let the points be A and B

A ( 5 , 1 ) ⇒ ( x₁ , y₁ )

B ( -3 , -5 )⇒ ( x₂ , y₂ )

Now, let's find the distance between theses two points:

Distance = [tex] \mathsf{ \sqrt{ {(x2 - x1)}^{2} + {(y2 - y1)}^{2} } }[/tex]

Plug the values

[tex] \mathsf{ \sqrt{ {( - 3 - 5)}^{2} + {( - 5 - 1)}^{2} } }[/tex]

Calculate

[tex] \mathsf{ \sqrt{ { ( - 8)}^{2} + {( - 6)}^{2} } }[/tex]

Evaluate the power

[tex] \mathsf{ \sqrt{64 + 36} }[/tex]

Add the numbers

[tex] \mathsf{ \sqrt{100} }[/tex]

Write the number in exponential form with a base of 10

[tex] \mathsf {\sqrt{ {10}^{2} } }[/tex]

Reduce the index of the radical and exponent with 2

[tex] \mathsf{10 \: units}[/tex]

-------------------------------------------------------------------------------

The distance formula is used to determine the distance ( d ) between two points. If the co-ordinates of the two points are ( x₁ , y₁) and ( x₂ , y₂ ) , the distance equals the square root of x₂ - x₁ squared + y₂ - y₁ squared.

Hope I helped!

Best regards!

Can someone please help!! ****This problem is multiple choice!

Answers

Answer:

I believe it's A) 302.94

Step-by-step explanation:

There are 360 degrees in a circle. So I enetered 360/112 in a calculator and got 3.214.

Then I multiplied 3.214 by 30pi and got 302.939 AKA 302.94. I did this because I looked at it like a ratio problem but idk if thats correct.

This answer should be letter 302.94 A.

At the end of the day, a bakery gives everything that is unsold to food banks for the needy. If it has 12 apple pies left at the end of a given day, in how many different ways can it distribute these pies among 6 food banks for the needy?

Answers

Answer:

462 ways

Step-by-step explanation:

The formula to use in solving this problem is given as the Combination formula

The Combination formula is given as

C(n , r) = nCr = n!/r! (n - r)!

We are told that a food bakery has 12 pies unsold at the end of the day which they intend to share to 6 food banks

n = 12, r = 6

In order to ensure that at least 1 food bank gets 1 pie, we have:

n - 1 = 12 - 1 = 11

r - 1 = 6 - 1 = 5

Hence,

C(11, 5) = 11C5

= 11!/ 5! ×(11 - 5)!

= 11!/5! × 6!

= (11 × 10 × 9 × 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1)/ (5 × 4 × 3 × 2 × 1) ×( 6 × 5 × 4 × 3 × 2 × 1)

= 462 ways

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