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Solve using substitution-2x-y=-9. 5x-2y=18

User Krumpli
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1 Answer

5 votes
Equation 1) -2x-y=-9
Equation 2) 5x-2y=18

Multiply all of equation 1 by 2, so that both equations have (2y) in them.

1) 2(-2x-y=-9)

Simplify.

1) -4x-2y=-18
2) 5x-2y=18

Subtract equations with each other.

-9x=-36

Divide both sides by -9.

x=4

Plug in 4 for (x) into equation 1.

-2x-y=-9

-2(4)-y=-9

Simplify.

-8-y=-9

Add 8 to both sides.

-y=-1

Divide both sides by -1.

y=1

(4, 1)

~Hope I helped!~

User Mattdedek
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