I have 60 coins both quarters and dimes. The combined total is 9.45. What are two equations I can use to solve this problem?

Step-by-step explanation:

Assuming the problem you want to solve is finding the number of each coin, you can let variables represent those numbers. I like to use mnemonic variables, such as q for the number of quarters, and d for the number of dimes.

The two equations you can write are based on the given information:

  q + d = 60 . . . . . . you have 60 coins

  .25q +.10d = 9.45 . . . . . their value is 9.45

You have 23 quarters and 37 dimes.

I like to solve these by substitution, using an expression to replace the variable representing the lowest-value coin.

  d = 60 -q . . . . . . . expression for the number of dimes

  .25q +.10(60 -q) = 9.45

  .15q +6.00 = 9.45 . . . . . eliminate parentheses, collect terms

  .15q = 3.45 . . . . . . . . . . .subtract 6.00

   q = 23 . . . . . . . . . . . . . . . divide by 0.15

   d = 60 -q = 37

180

step-by-step explanation: