Assuming the equations are:
x + y. + z = 10 1
2x + 4y + 2z =32 2
-x +8y - 3z = 42 3
Multiply eq 3 by 2 and add to eq 2:
20y -4z = 116 4
Multiply eq 1 by 2 and subtract it from eq 2:
2y = 12; then y = 6
Substitute in eq 4:
Then -4z = 116 - 120 = -4; z = 1
Substitute in eq 1; then
X = 10 - 6 - 1 = 3
Answer:
X = 3
Y = 6
Z = 1