Answer:
- q+d = 60
- .25q +.10d = 9.45
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
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You have 23 quarters and 37 dimes.
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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
