There are 9 more quarter then dimes.if the total value of the coins is 6.8, how ,any quarters are there?

3 answers

Is the total value $6.80?

If so, then let Q be the number of quarters and D be the number of dimes.

You know that
Q -D = 9, and
0.25Q + 0.1D = 6.80
Solving bu substitution,
0.25Q + 0.1(Q-9) = 6.80
0.35Q = 7.70
Q = 22
Now solve for D
omg ty u are a super pro
ty, yw :)