I’m going to solve this with a graphing calculator… if you need it without one I can do that too just let me know :)
When you have 3 variables you need to solve for, you need 3 equations. So, make sure you order every equation in a format of ax + by + cz = d. even if there is a 0.
so the first equation is good. second equation, move ur z over to make x+y-z. third equation, move x to left and constant to right and add a 0y to make -x+0y+z=-1
Now on ur calculator you open up the matrix menu, create a new matrix, and enter:
1 1 1 6
1 1 -1 0
-1 0 1 -1
Now perform the matrix and your answer to each variable is at the end of each line to the matrix :)
again lmk if you need the non-calc way