SOLUTION: Please, Please help me. I just don't understand what to do. I've tried equation possible. Otis has a box of coins. There are 44 coins in all. The box contains pennies, dimes

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Question 156231This question is from textbook
: Please, Please help me. I just don't understand what to do. I've tried equation possible.
Otis has a box of coins. There are 44 coins in all. The box contains pennies, dimes and quarters. The number of dimes is equal to the number of pennies. The total value is $4.37. How many of each denomination of coins does he have in the box? This question is from textbook

Answer by ptaylor(2198) (Show Source):
You can put this solution on YOUR website!
Let x=number of dimes
Then x will also equal the number of pennies
And let y=number of quarters
Now we are told that:
0.01x +0.10x +0.25y=4.37
0.11x+0.25y=4.37 multiply each term by 100
11x+25y=437--------------------------------------eq1
We are also told that:
2x+y=44 or
y=44-2x-------------------eq2
Substitute y=44-2x from eq2 into eq1
11x+25(44-2x)=437 get rid of parens
11x+1100-50x=437 subtract 1100 from each side
11x+1100-1100-50x=437-1100 collect like terms
-39x=-663 divide each side by -39
x=17------------------------------number of dimes and also number of pennies
Substitute x=17 into eq2
y=44-2*17= 10-----------------------number of quarters
CK
2*17+10=44
44=44
and
0.25*10+0.01*17+0.10*17=4.37
2.50+0.17+1.7=4.37
4.37=4.37

Hope this helps--ptaylor