Question

X=9y+7
x=4y-8
Solve the system of equations by the substitution method

Answer 1

x= -20,y= -3

Explanation:

1. x=9y+7

2. x=4y-8

so substitute equation 2 into equation 1

x=9y+7

4y-8=9y+7

4y-9y=7+8

-5y=15

divide both sides by -5

y= -3

substitute in equation 2

x=4(-3)-8

x= -12-8

x= -20