Question

I have19 coins that are worth a total of $1.10.If they consist only of dimes and nickels, then how many nickels do I have?

Answer 1

n + d = 19 so d = 19-n

5n + 10 d = 110 cents

5 n + 10(19-n) = 110

5 n + 190 -10 n = 110

-5 n = -80

n = 16

Answer 2

you are right but to explain a little more you would need to show your steps on how you got the dimes for it to make more sense like this.

d= number of dimes
10d= amount of dimes
n= number of nickels
5d= amount of nickels


d+n =19
10d+5n= 1.10
n=19-d = # of nickels so...
10d+5(19-d)=1.10 solving...
10d+95-5d=1.10
5d=15 and then divided each side by 5 and get 3 dimes. To get the number of nickels all you would have to do is subtract 19 from 3 and get 16 nicles and that would be it