can you solve this problem

Question

A change jar contains  85 coins that total $7.20. The coins are either dimes or nickels.  How  many  dimes and nickels are in the jar

Answer 1

A change jar contains 85 coins that total $7.20. The coins are either dimes or nickels.

x + y = 85, y = 85 - x

x(5) + y(10) = 720

x(5) + (85 - x)(10) = 720

5x + 850 - 10x = 720

-5x = -130

x = 26 nickels

y = 59 dimes