Solve the system by substitution

Equation A: -2x+y = 1

Equation B: -x+y = -1

A:

Substitute for y in equation B

Substitute for x back into A to get y

A:

Does it check?

A:

B:

-2(-2) +(-3) = 1
             4-3 = 1

Now try this Example: Solve by substitution.

x + 3y = 2
2x - y = 1