Question

Sue has $2.20 in dimes and nickels. If she has 13 more dimes than nickels, how many of each coin does she have?

Answer 1

10d+5n=220
divide both sides by 5
2d+n=44

d=13+n
sub 13+n for d in other equatin

2(13+n)+n=44
26+2n+n=44
26+3n=44
minus 26 both sides
3n=18
divide both sides by 3
n=6
sub back

d=13+n
d=13+6
d=19


19 dimes
6 nickles