Question

really confused! Morgan has nickels, dimes, and quarters in her piggy bank. In total, she has 45 coins, with a value of $5.25. if she has three more dimes than all the nickels and quarters combined, how many of each type of coin does she have?

Answer 1

ok, let's call the nuckels n, dimes d, and quarters q. can you set up any systems of equations?

Answer 2

n+d+q=45
5.25= 0.05n+0.10d+0.25q

Answer 3

ok, there's one more you can make with the last sentence

Answer 4

not quite sure what to do after that

Answer 5

ok, wellshe has three more dimes that the total of nickels and quarters so
d = 3 + n + q
does that make sense?

Answer 6

yes actually i got that far in class today, then i couldnt get past that

Answer 7

ok, well substitute the third equation in for d into the first two equations

Answer 8

5.25=0.05n+0.1(3+n+q)+0.25q
but then you're still left with two variables

Answer 9

do you isolate one of them and substitute again?

Answer 10

exactly.
solve those two equations as you would a noral system of equations

Answer 11

oh so 45=n+(3+n+q)+q
and 5.25=0.05n+0.1(3+n+q)+0.25q

Answer 12

exactly!
can you do it from here?

Answer 13

yes thank you so much :)

Answer 14

anytime :)

Answer 15

Do you think I could get rid of the decimals and then put them in at the end? Do you think I would lose marks doing that?

Answer 16

no, you wouldn't, but you have to be really careful.
what you want to do is multiply the whole thing by 100, so that it's like you're doing it in terms of cents and not dollars, ok?

Answer 17

Alright, I think I will still to decimals :P

Answer 18

wait one last question

Answer 19

sure

Answer 20

Actually wrong one :P