Answer:
8 dimes and 14 quarters.
Explanation:
d and q are the number of dimes and quarters, respectively.
"22 coins, all dimes and quarters"
d+q = 22
d = 22-q
"total value is $4.30"
0.10d + 0.25q = 4.30
substitution
0.10(22-q) + 0.25q = 4.30
2.2 + 0.15q = 4.30
q = 14
d = 22-q = 8
8 dimes and 14 quarters.