Question

4x + 4y + 2z = 8
x - y -z = 0
4y - 2z = -15
x = 2, y = -2, z = 4; (2, -2,4)
Is (2,-2,4) a solution of the system of equations? Yes or no?

Answer 1

The answer is no, because the first two equations are right but the third equation equals -16 instead of -15. So the answer is no (2,-2,4) is not the solution to all the system of equations.