Question

solve the system:
x+y-z=2
2x+y+z=3
3x+y+z=5

Answer 1

Reduce the system to 2 equations with 2 variables by adding equations 1 and 2.
That will eliminate z. Eliminate z again by adding equations 1 and 3.
You will then have 2 equations with 2 variables. Solve that system.

Answer 2

could you show what the numbers would look like?

Answer 3

Did you add the first two equations?