Question 972980
x=quarters
38-x= dimes

.25x + .10 *(38-x)=7.70   all units dollars and cents.

.25x + 3.80-.10x=7.70

.15 x =3.90
15 x=390

x=26
38-x =12

26 quarters  ($6.50)
12 dimes  ($1.20)