Question

Solve the system x-2y+2z=9 y+2z=5 z=3 Enter the answer as an ordered triple, (X,Y,Z)

Answer 1

The answer is (1, -1, 3)

Answer 2

The last equation says z = 3, so that in the second equation we get

y + 2z = y + 6 = 5   ==>   y = -1

and in turn, the first equation tells us

x - 2y + 2z = x + 2 + 6 = x + 8 = 9   ==>   x = 1

So the solution to the system is (x, y, z) = (1, -1, 3).