Question 502266
A cash register contains only dimes and quarters.  There are 65 coins worth $12.80 in the register.  How many dimes and quarters are in the register?

I have tried to set up but can't figure it out.

i.e. I tried: 65 - .10d = quarters
65 - .10d + ??? = 12.80
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65 - d = q
10d + 25q = 1280
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