5(2x) - 3 = 20x + 15
10x - 3 = 20x + 15
-3 = 20x + 15 - 10x subtract 10x to both sides.
-3 = 10x + 15
-3 - 15 = 10x subtract 15 to both sides
-18 = 10x
-18/10 = x divide both sides by 10
x = -9/5 reduce to a smaller fraction and this is your answer.
hope this helps, God bless!