December 18, 2011 7:43 pm at 7:43 pm #601178supergirl613Member
K, so I have this math problem that I have absolutely have NO clue how to do it. It’s an inequalities problem I think.
Jo has 37 coins(nickels, dimes and quarters) equaling up to $5.50. She has four more quarters than nickels.
How many dimes does she have?
Can someone please help me?? I’m really stuck!!!!December 18, 2011 8:48 pm at 8:48 pm #835743mischiefmakerMember
# P T
nickels x 5 5x
dimes 37-(x+x+4) 10 10(37-x+x+4)
quarters x+4 25 25(x+4)
I hope that helps…that’s about all I remember 🙂
I don’t know why its not staying in chart form, sorry!December 18, 2011 9:04 pm at 9:04 pm #835744LifeisgreatMember
Let x=number of nickels
Then x+4=number of quarters
So the number of dimes would be:
33-2x —- is the number of dimes
(lets deal in pennies)
collect like terms
subtract 430 from each side
divide each side by 10
number of nickels
number of quarters
number of dimes
550=550December 18, 2011 9:08 pm at 9:08 pm #835745supergirl613Member
Please someone help!!!December 18, 2011 9:17 pm at 9:17 pm #835746RazzleMember
Just google the question and a whole list of explanations come up. the answer is 9 dimes.December 18, 2011 9:41 pm at 9:41 pm #835747thecuriousoneMember
Here you go:
Set the number of nickels as “n”, the number of dimes as “d”, and the number of quarters as “q”.
There are a total of 37 coins. Therefore:
You also know that the total in dollar amounts is equal to $5.50. Therefore:
In the first equation, we can set q = n+4 (as there are 4 more quarters than nickels). Resetting the first equation:
Solve for “d” in terms of “n”:
Now we set the second equation (using q=n+4):
Now you can plug the “d=33-2n” value to the above equation to solve for “n”:
Do all the annoying math, and the final answer is n=12. That gives you the number of nickels. Finally:
and that’s your answer! Double check your work and make sure the math is right:
Hope that answers your question! Just keep in mind the moral of the equation: if you have multiple variables (like you do here), you need to set up equations to solve for a variable in terms of a main variable – which in this case I made “n” as our main variable.
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