Question

Solve the following system of equations:
4x − 2y − z = −5
x − 3y + 2z = 3
3x + y − 2z = −5
(0, 1, 3)
(0, −1, 3)
(0, 1, −3)
(0, −1, −3)

Answer 1

A) 4x − 2y − z = −5
B) x − 3y + 2z = 3
C) 3x + y − 2z = −5
Looking at ALL 4 solutions, x =0 in all of them.
So, let's say x = 0, eliminate the "x's" and just keep equations B and C

B) -3y + 2z = 3
C) y − 2z = −5
Add B) and C)
-2 y = -2
y = 1

1 − 2z = −5
-2z = -6

z = 3

and x = 0