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3 years ago

Solve this system using elimination (20 POINTS) 4x-7y=3 x-7y=-15

Mathematics

1 answer:

stiv31 [10]3 years ago

4 0

Answer:

x = 6, y =3

Step-by-step explanation:

4x-7y=3

x-7y=-15

Multiply the first equation by -1

-4x+7y=-3

Then add this to the second equation to eliminate y

-4x+7y=-3

x-7y=-15

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

-3x +0y = -18

-3x = -18

Divide by -3

-3x/-3 = -18/-3

x = 6

Now find y

x -7y = -15

6 -7y = -15

Subtract 6 from each side

6-7y-6 = -15-6

-7y = -21

Divide by -7

-7y/-7 = -21/-7

y =3

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In math class, 4 students complete individual surveys to determine the percentage of high school teachers that have a second job

dlinn [17]

Answer:

Option D) B and C

Step-by-step explanation:

we know that

To find out the percentage of high school teachers that have a second job, divide the number of teachers that have a second job by the total number of teachers

Survey A

$\frac{28}{110}=0.2545$

Convert to percentage

$0.2545(100)=25.45\%$

Survey B

$\frac{27}{90}=0.3$

Convert to percentage

$0.3(100)=30\%$

Survey C

$\frac{21}{70}=0.3$

Convert to percentage

$0.3(100)=30\%$

Survey D

$\frac{32}{80}=0.4$

Convert to percentage

$0.4(100)=40\%$

Compare the percentages

Surveys B and C have the same percentage

therefore

Surveys B and C show proportional results, because the ratio of the number of teachers that have a second job by the total number of teachers is equal (this number is the constant of proportionality k in a proportional relationship between two variables)

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3 years ago

Is 1/5 less than 5/8

iren [92.7K]

1/5 is less then 5/8

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3 years ago

URGENT: Solve the following: (5x10^9)x(7x10^5)

Elanso [62]

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