Question

Use the substitution method to solve the system of equations.

{y=x−8

2x + 3y=1

What is the solution?


(4, −4)

(2, −6)

(5, −3)

(0, −8)

Answer 1

Substitute y = x - 8 for y in 2x + 3y = 1:
2x + 3(x - 8) = 1
2x + 3x - 24 = 1
5x - 24 = 1
5x = 25
x = 5
Substitute 5 for x in y = x - 8 and 2x + 3y = 1
y = 5 - 8 --> y = -3
2(5) + 3y = 1 --> 10 + 3y = 1 --> 3y = -9 --> y = -3
x = 5 and y = -3