\(\begin{align*} x + 3y + 2z &= 1,\\ -3x + y + 5z &= 10,\\ -2x - 3y +z &= 7. \end{align*}\)
x + 3y + 2z = 1 (1)
-3x+ y + 5z =10 (2)
-2x -3y + z = 7 (3)
Adding (1) and (3) we get
-x +3z = 8 (4)
Multiply (2) by 3 = -9x + 3y + 15z = 30
Add this to (3) and we get
-11x + 16z = 37 (5)
Multiply (4) by -11 and we get 11x - 33z = -88
Add this to (5) and we get that
-17z = - 51
z = -51/-17 = 3
Sub yhis into (4) to find x
-x + 3(3) = 8
9 - 8 = x
1 = x
And using (1) to find y
1 + 3y + 2(3) = 1
3y + 6 =0
3y = -6
y = -6/3
y = -2
{ x, y, z } = { 1, -2, 3 }