Question

Solve the system of equations x + y = 4 and -9x + 7y = -84 by combining the
equations.

Answer 1

x = 7

y = -3

Explanation:

x + y = 4 (Multiply this by 9)

-9x + 7y = -84

9x + 9y = 36

-9x + 7y = -84

16y = -48

y = -3

x + y = 4

x - 3 = 4

x = 7