Question

Solve each system using substitution:
1. 4x - 5y= -15
y= -3x + 22

Answer 1

4x - 5y = -15
y = -3x + 22

Plug in your y= equation into the y variable in the other equation

4x - 5 (y) = -15
^^
y = (-3x + 22) = -15

4x - 5 (-3x + 22) = -15

Distribute

4x + 15x - 110 = -15

Combine like terms and add 110 over to -15

19x = 95

Then, divide the whole equation by 19

x = 5

Then, plug in your x into your y= equation

y = -3 (5) + 22
y = -15 + 22
y = 7

x = 5
y = 7
(5, 7)