Explanation:
x + 3y + 2z = 8
3x + y + 3z = -10
-2x - 2y - z = 10
we solve this by eliminating variables or expressing sine variables by others, and then solve for the remaining one. with that value we then cancer back to solve for the other variables.
in our case the easiest way is the elimination via combinations of equations.
let's first multiply equating 1 by -3 and then add that to equation 2 :
-3x - 9y - 6z = -24
3x + y + 3z = -10
----------------------------
0 - 8y - 3z = -34
8y + 3z = 34
then multiply equation 1 by 2 and add it to equation 3 :
2x + 6y + 4z = 16
-2x - 2y - z = 10
--------------------------
0 4y + 3z = 26
now we subtract this result from the previous result :
8y + 3z = 34
- 4y + 3z = 26
----------------------------
4y 0 = 8
y = 8/4 = 2
4×2 + 3z = 26
3z = 18
z = 18/3 = 6
x + 3×2 + 2×6 = 8
x = -10
so,
x = -10
y = 2
z = 6