Question

solving systems of equations by substitution -3x-4y=2 and 3x+3y=-3

Answer 1

3x + 3y = -3

3 (x+y) = -3
Dividing both sides by 3:

x + y = -1

y = -1 - x ------(1)

-3x - 4y = 2 ------- ( 2)

Substituting equation (1) in (2)

- 3x - 4(-1-x) = 2

-3x +4 + 4x = 2

x = -2

y = -1 - 2 = -3