10. Check
If
x = 2
y = 1
z = 3
The first equation becomes
2(2) + 3(1) + 3 = 10
4 + 3 + 3 = 10
10 = 10
The second equation becomes
(2) - (1) + (3) = 4
2 - 1 + 3 = 4
4 = 4
The third equation becomes
4(2) - (1) - 5(3) = - 8
8 - 1 - 15 = - 8
- 8 = - 8
and the solutions check in all three equations.