Question

Tell which equation you would use to isolate a variable in order to solve the system using substitution. Explain your reasoning.

2x + y=-10
3x-y=0

Answer 1

3x-y=0 is very simply seen to be y=3x, and then you can use this value of y in the other equation to get:

2x+y=-10 becomes:

2x+3x=-10

5x=-10

x=-2, making y=3x become:

y=3(-2)

y=-6, so the solution to the system of equations is the point (-2, -6)

Answer 2

The solution to the system of equations is the point (-2, -6)