Step-by-step explanation:
4z = 8
z = 8/4
z = 2
3x - 2z = 11
3x - 2.2 = 11
3x - 4 = 11
3x = 11 + 4
3x = 15
x = 15/3
x = 5
x - 4y + z = 11
5 - 4y + 2 = 11
-4y = 11 - 5 - 2
-4y = 4
y = 4/-4
y = -1
Solution → {x,y,z} = {5,-1,2}
