First things first, write out your equation without the substitution.
2x+ 2y= 10
Now, put in the substitution.
2x+ 2• 2= 10
Combine like terms.
2x+ 4= 10
Now that your equation it simplified, you need to reverse the problem and put everything on the other side.
2x+ 4= 10
- 4 - 4
2x = 6
2x=6
— —
2 2
X= 3
So the final answer is x=3
