x=quarters

3x=dimes

4.95=total

so you take the worth of the coins times the amount, add them together for the total.

3x(.10)+.25x=4.95

.30x+.25x=4.95

.55x=4.95

.55x/.55=4.95/.55

x=9 (quarters)

3x=27 (dimes)

check your answer:

9 quarters equals $2.25

27 dimes equals $2.70

add them together and you get $4.95