College algebra

Question

In a bag contains 515 coins worth $102.10. There were three types of coins:nickels, dimes and quarters. If the bag contained the four times as many quarters as nickels, how many of each type of coin was in the bag?

Answer 1

515 = N+D+Q, Q=4N

515 = N+D+4N = 5N + D

10210 = 5N+10D+25Q= 5N+10D+25(4N)= 105N+10D

10210=105N+10D

5150= 50N+10D subtract to get

5060= 55N

N = 5060/55 = 92 nickels

Q =4N = 4(92)= 368 quarters

D =515-5(92) =515-460=55 dimes