Solve the system of linear equations by substitution. Check your solution.

Question

2y + x = -4

y - x = -5

Answer 1

Hi Ashlyn,

2y + x = -4 Eq 1

y - x = -5 Eq 2

From Eq 1

X = -4 -2y

Plug in value of X in Eq 2

Y - ( -4 -2Y ) = -5

Y +4 +2Y = -5

3Y + 4 = -5

3Y = -5 -4

3Y = -9

Y = - 3

Plug in Eq 1

2(-3)+ X = -4

-6 +X = -4

X = -4 +6

X = 2