Hello!
You solve this like an algebraic equation
You first distribute the 4 and 2
4x - 20 = 2x - 20 + 2x
Combine like terms
4x - 20 = 4x - 20
subtract 4x from both sides
-20 = 0x - 20
Add 20 to both sides
0 = 0
This means that there are infinite solutions to the equation.
Hope this helps!