Substitution method please help :3

Worth 15 points 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? a= p = 1/4 b= p+0.25p c=(p + 1/4)p d=5/4p 0.25p choose 2 answers

What is a correct first step in solving the inequality-4(3-5x)> -6x+9

Arestaurant offers delivery for their pizzas. the total cost the customer pays is the price of the pizzas, plus a delivery fee. one customer pays $23 to have 2 pizzas delivered. another customer pays $59 for 6 pizzas. how many pizzas are delivered to a customer who pays $86?