You can
put this solution on YOUR website!I take a little different interpretation of your problem, assuming that there were NO PARENTHESES around the x-2! I think the solution by the other tutor is wrong!!
20(2) = 5*x -2
40 = 5x-2
Add +2 to each side:
42 = 5x
Divide both sides by 5:
x= 42/5 or 8.4
R^2 at SCC