Question 953646
q=quarters; d=dimes=6q; n=nickels=2q
$0.05n+$0.10d+$0.25q=$2.85 Substitute for d and n
$0.05(2q)+$0.10(6q)+$0.25q=$2.85
$0.10q+$0.60q+$0.25q=$2.85
$0.95q=$2.85 Divide each side by $0.95
q=3 ANSWER 1: There were 3 quarters.
d=6q=6(3)=18 ANSWER 2: There were 18 dimes.
n=2q=2(3)=6 Answer 3: There were 6 nickels.
CHECK:
$0.05n+$0.10d+$0.25q=$2.85 
$0.05(6)+$0.10(18)+$0.25(3)=$2.85
$0.30+$1.80+$0.75=$2.85
$2.85=$2.85