Can you show me how to do this?

(4x+66)/3 = (13-3x)/4      cross-multiply

4 (4x + 66) = 3(13 - 3x)   simplify

16x + 264 = 39 - 9x      add 9x to both sides

25x + 264   = 39         subtract 264 from both sides

25x  = -225     divide both sides by 25

x  =  - 9