I don’t understand at all

Handsome jack is buying a pony made of diamonds. the price of the pony is p dollars, and jack also has to pay a 25% diamond pony tax. which of the following expressions could represent how much jack pays in total for the pony?

If 5x - 2 = -12, then x = a) -50 b) -4.4 c) -2.8 d) -2

2f(x)= x+3 if 4 < x < 8 2x if x 28 2