Answer
All equations are true, so the solution is correct.
Work Step by Step
In order to verify that the given values are solutions, we substitute the values of all variables into all three equations to ensure that they produce a true result:
$$ 3(1) + 3(-1) +2(2)=4 \\ 4=4$$
For equation two:
$$1 - (-1) -2 = 0 \\ 0=0$$
For equation three:
$$2(-1)-3(2)=-8 \\ -8=-8$$
All equations are true, so the solution is correct.
