please show me how to solve this equation.I need step by step, because I just do not get it.

7/2x + 1/2x = 3x + 12/2 + 5/2x
HELP ME PLEASE!!!!!!

I am going to guess that you mean:

(7/2)x + (1/2)x = 3x + 12/2 + (5/2)x
multiply all terms, both sides by 2
7x + x = 6x + 12 + 5x
-3x = 12
x = -4