Question

Use either substitution or elimination to solve the following system of equations, find the solution. Show all of your work.

7x + 4y = -5
-2x + 5y = 26


I attached a picture of the problem.

Answer 1

Elimination:

-5 (7x+4y=-5) -35x + -20y = 25
4 (-2x+5y=26) -8x + 20y = 104

Y's cancel out

-43x = 129 Divide each side by -43

X = -3

7(-3) + 4y = -5
-21 + 4y = -5 Add 21 to each side
4y = 16 Divide each side by 4
y = 4