SOLUTION: A piggy bank contains 60 coins, all dimes and quarters. The total amount of money is $11.40. How many of each is there? Please Help, I need this for my Algebra

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Question 918403: A piggy bank contains 60 coins, all dimes and quarters. The total amount of money is $11.40. How many of each is there?
Please Help, I need this for my Algebra

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +d+ = number of dimes
Let +q+ = number of quarters
----------------------------
(1) +d+%2B+q+=+60+
(2) +10d+%2B+25q+=+1140+ ( in cents )
----------------------------------
(2) +2d+%2B+5q+=+228+
Multiply both sides of (1) by +2+
and subtract (1) from (2)
(2) +2d+%2B+5q+=+228+
(1) +-2d+-+2q+=+-120+
+3q+=+108+
+q+=+36+
and
(1) +d+%2B+q+=+60+
(1) +d+=+60+-+36+
(1) +d+=+24+
---------------
There are 24 dimes and 36 quarters
check:
(2) +10d+%2B+25q+=+1140+
(2) +10%2A24+%2B+25%2A36+=+1140+
(2) +240+%2B+900+=+1140+
(2) +1140+=+1140+
OK