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Solve by substitution 6x-4y=18, -x-6y=7

1 Answer

11 votes

Answer:

(2,-1.5)

Explanation:

6x-4y=18

-x-6y=7

Switch the second equation from standard form to y=mx+b form

-x-6y=7→ -x=7+6y → multiply both sides by -1→ x=-7-6y

Substitute all of the things that equal x into the other equation into x

6x-4y=18→ 6(-7-6y)-4y=18

Simplify

-42-36y-4y=18

Bring - 42 to the other side and add like terms

-42-36y-4y=18→ -40y= 60

Solve for y

y=-1.5

Choose an equation and plug y in it.

-x-6(-1.5)=7

-x+9=7

-x=-2

Multiply both sides by -1

x=2

User Mark Vanzuela
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