The answer is
x=10+2y
Steps:
2(x-2y)=20
x-2y=20/2 (in fraction form 20/2)
x-2y=10
X=10+2y
2x-4y=20
Add both sides by -4y
2x=20+4y
Then divide both sides by 2 and you get your answer
x=2y+10
