4.37.-On January 1st, Frank bought a used car for $72,000 and agreed to pay it as follows: ¼ down payment; the balance to be paid in 36 equal monthly payments; the first payment due February 1; an annual interest rate of 9%, compounded monthly. a)What is the amount of Frank’s monthly payment?b)During the summer, Frank made enough money to pay off the entire balance due on the car as of October 1. How much did Frank owe on October 1 (of the initial year)?

(a) So Frank’s monthly payment = 2/3 ($7,200) (A/P, 0.75%, 36) (6 points)

 = $4,800 (0.0318)

 = $152.64

(b) Frank owed the October 1 payment plus the present worth of the 27 additional payments.  

Balance  = $152.64 + $152.64 (P/A, 0.75%, 27) (6 points)

 = $152.64 (1 + 24.36)

 = $3,870.95

Explanation:

x=3

step-by-step explanation:

this is really simple i saw that there was only one term (5x) and thought if that was 15 what would i have to multiply everything else to get it there? well if 5x became 15 then x would have to be 3 so plug the 3 in the x for the other equations and you get 15 for the other ones. so there you go. : )