Solve for X. Will give a lot of points. HELP!!!

Answer:
7).
RT = RS + ST
[tex]10 = (2x - 20) + (2x - 18) \\ 10 = (2x + 2x) + ( - 20 - 18) \\ 10 = 4x - 38 \\ 4x = 10 + 38 \\ 4x = 48 \\ { \boxed{x = 12}}[/tex]
8).
LN = LM + MN
[tex](5x - 2) = 12 + (x + 2) \\ (5x - x) = 12 + 2 + 2 \\ 4x = 16 \\ { \boxed{x = 4}}[/tex]