Question 838722
d = number of dimes
q = number of quarters
d = q - 7
0.10d + 0.25q = 3.85
substitute (q - 7) for d
0.10(q - 7) + 0.25q = 3.85
0.10q - 0.70 + 0.25q = 3.85
0.35q - 0.70 = 3.85
add 0.70 to each side
0.35q = 4.55
divide each side by 0.35
q = 4.55/0.35
q = 13
d = 13-7 = 6
$0.60 in dimes + $3.25 in quarters is $3.85