You can solve for y, but you can't find a value for y. Your equation has two variables, and neither is given a value. Can you solve for y? The WAY to solve it,....Three steps.
Focus on "y".
The given equation: 2x + [24-2 (y)] = 20
What is the first thing you see that is done to y?
What is the next thing that you see done to that?
What is the NEXT thing you see done to THAT?
You want to perform the inverse of each of those operations, and in reverse order as was done to y. Try to work through this for several minutes, before continuing....
You need y on one side and x on the other side of equality symbol.
Additive inverse of 2x;
Additive inverse of 24;
Multiplicative inverse of -2;
You are done.