You have inadvertently left out some of the instructions for this problem.
22 + 0.15p =c could be solved for p; that's one thing you could do now.
Subtracting 22 from both sides, 0.15p = c - 22
Dividing both sides by 0.15, p = (c-22)/0.15 , or p = (20/3)(c-22).