X-2y=1

x+3y+z=0

2x-2z=18

Solve equation [2] for the variable z

[2] z = - x + 3y

/ / Plug this in for variable z in equation [3]

[3] 2x - 2• (-x + 3?) = 18

[3] 4x = 18

/ / Solve equation [1] for the variable x

[1] x = 2y + 1

/ / Plug this in for variable x in equation [3]

[3] 4• (2?+1) = 18

[3] 0 = 14 = > NO solution