A boy has twice as many nickels as he has pennies, and he has 5 less dimes than nickels. If he has $4.46 in all, how many coins of each kind does he have?
10d+5n+1p=446 subsitute n/2 for p subsitute n-5 for d 10(n-5)+5n+n/2=446 times 2 both sides 20(n-5)+10n+n=892 expand 20n-100+10n+n=892 31n-100=892 add 100 both sides 31n=992 divide both sides by 31 n=32
