Solve the following system.

Question

4x+3y−z=−18
3x−2y+z=1
2x+5y−z=−20

Answer 1

4x+3y−z=−18
3x−2y+z=1
------------------------ add
7 x + 1 y = -17

3x−2y+z=1
2x+5y−z=−20
------------------------- add
5 x + 3 y = -19

multiply 7 x + 1 y = -17 by 3
21 x + 3 y = - 51
5 x + 3 y = -19
------------------------- subtract
16 x = -32
x = -2
now go back for y and z