Question 857828
X + 5 = 2(x-15)
Distribute
X + 5 = 2x - 30
Subtract x from each side
5 = x - 30
Add 30 to each side
35 = x
.
Let's prove it by putting it back into the equation.
In five years, you will be 40.
Fifteen years ago, you were 20.
Is 40 twice 20?  yes.  Success!