Solve the following system of equations by the substitution

Solve the following system of equations by the substitution method.

Solution

9x - 5y = -89

4x + 42 = y

put equ 2 in equ 1

9x - 5*(4x+42) = -89

9x - 20x - 210 = -89

11x = -121

x = -11

y = 4x + 42

y = 4*(-11) + 42

y = -2