In one of the equations we need to get a variable by itself. Let's try the first one and try to get 'x' isolated by taking away y from the left side. That means we have: x = 57 - y.
Now let's plug this into the second equation, we have: (57 - y) - y = 33.
Let's release the parentheses and combine the negative y's to get: 57 - 2y = 33
Now take away 57 to try and isolate '2y', we get: -2y = -24.
Now divide by -2 to get y = 12.
Lastly plug 12 into any equation as y and solve for the x.