## College Algebra (10th Edition)

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.