Question

Solve the following system of equations.

x + 3y + 2z = -16
2x - y + 2z = -15
2x - 2y - z = 1


A (-3, -1, -5)
B (-3, 5, -2)
C (2, -4, -3)
D (4, 4, -1)

Answer 1

-1 (x + 3y + 2z = -16)
2x - y + 2z = -15
x -4y = 1
x = 1 + 4y
2x - 2y - z = 1
z = 2x -2y -1
z = 2 (1 +4y) -2y -1
z = 6y + 1 : y < -1/6 z negative can't be B , C, D
y = -1 gives z = -5 checks
y = -1 gives x = -3 Therefore A is answer