2x-3y=-7 and 3x+4y=15

Question

2x-3y=-7

3x+4y=15

 

solve for x and y by the addition elimination or substitution method

Answer 1

2x-3y=-7

3x+4y=15

Multiply the first equation by 3 and the second equation by 2.

3(2x-3y)=3(-7)

2(3x+4y)=2(15)

6x-9y=-21

6x+8y=30

Subtract the second equation from the first equation.

-17y=-51

y=(-51)/(-17)

y=3

Substitute 3 for y in either original equation.

2x-3(3)=-7

2x-9=-7

2x=9-7

2x=2

x=1

x=1, y=3