Question

Solve the system of equations x+y=-1 and 5x-7y=79 by combining the equations.

Answer 1

9514 1404 393

Answer:

(x, y) = (-6, -7)

Explanation:

Multiply the first equation by 7 and add that to the second.

7(x +y) +(5x -7y) = 7(-1) +(79)

12x = 72

x = 6

y = -1 -x = -1 -6 = -7

The solution is (x, y) = (6, -7).