what is the solution ?

Question

Antoinette has ninety-seven nickels and dimes totaling $7.10. How many of each coin does she have?

Answer 1

Answer 2

n + d = 79

0.05n + 0.1d = 7.1

Solve the first for n or d. I'll do d.

d = 79 - n

Suuuuubstitute!

0.05n + 0.1(79 - n) = 7.1

0.05n + 7.9 - 0.1n = 7.1

-0.05n = -0.8

n = 16 nickles

d = 79 - 16

d = 63 dimes