SOLUTION: i have eight more quarters than dimes. if the coins are woth $6.20, how many dimes are there?

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Question 225103: i have eight more quarters than dimes. if the coins are woth $6.20, how many dimes are there?
Answer by LtAurora(115) About Me  (Show Source):
You can put this solution on YOUR website!
Our given equations are:
Q=8%2BD
.25Q%2B.1D=6.20
Plug the first eq. into the second:
.25%288%2BD%29%2B.1D=6.2
Simplify:
2%2B.25D%2B.1D=6.2
Move the 2 over and combine like terms:
.35D=4.2
Divide both sides by .35:
D=12
So, using our first equation:
Q=8%2B12
Q=20
Checking our work: 20 quarters = $5 and 12 dimes = $1.20. The sum of those is $6.20, so we're good.