Question

Solve the system by elimination:
-2x + 2y + 3z = 0
-2x - y + z =-3
2x + 3y + 3z = 5

How do I do this? I need steps to understand please....

Answer 1

(1a) -2x + 2y + 3z = 0
(2a) -2x - y + z =-3
(3a) 2x + 3y + 3z = 5

2a from 1a and add 1a to 3a to get

(1b) 3y + 2z = 3
(2b) 5y + 6z = 5

Now, just by inspection, we see that y=1,z=0 fit these two equations. Or, you can subtract 2b from 3 times 1b to eliminate z.

In any case, just use any of the 1st 3 equations, knowing y=1 z=0, to get x.