Question

solve the following system of equations.

5x + y = -9
-5x + 2y = 0

Answer 1

Solve for ONE of the variables in ONE of the equations, then plug that into the OTHER equation.

For example if you have

1. x + 3y = 5
2. 2x - 6y = -2

Solve for x in eq. 1. -----> x = 5 - 3y
Plug 5 - 3y into eq. 2 ----->
2(5-3y)-6y= -2
10-6y-6y=-2
10-12y=-2
-12y=-2-10
-12y=-12
y = 1

Then plug y=1 into one of the equations to solve for x.
x + 3(1)= 5
x+3=5
x=5-3
x=2

Finally if you want to check your answer, plug x and y into one or both equations

2 + 3(1)= 5
2+3=5, check!
2(2)-6(1) = -2
4-6=-2, check!