Respuesta :

The soultion Is      p = -1
1st combine like terms by moving all of the terms with p to one side, and all of the other terms to the other side.

-6p - 21 = 3p -12
-21+12=6p+3p
-9=9p

Divide out the coefficient from both sides

-9/9 = 9p/9

The final answer is
-1=p