-20=-5+3x

To solve for x, we first want to get rid of the terms on the right side of the equation.

-20 = -5 + 3x

Add 5 to both sides:

-20 + 5 = 3x

-15 = 3x

Now divide both sides by 3 to solve for x:

-15/3 = x

-5 = x

Therefore, x = -5.