SOLUTION: Joe has a collection of nickels and dimes that is worth $5.65. If the number of dimes were doubled and the number of nickels were increased by 8, the value of the coins would be $1

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Question 439540: Joe has a collection of nickels and dimes that is worth $5.65. If the number of dimes were doubled and the number of nickels were increased by 8, the value of the coins would be $10.45. How many dimes does he have?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let n = number of nickels he has
Let d = number of dimes he has
given:
(1) +5n+%2B+10d+=+565+ (in cents)
(2) +5%2A%28n%2B8%29+%2B+10%2A%282d%29+=+1045+ (in cents)
-----------------------------
(2) +5n+%2B+40+%2B+20d+=+1045+
(2) +5n+%2B+20d+=+1005+
Subtract (1) from (2)
(2) +5n+%2B+20d+=+1005+
(1) +-5n+-+10d+=+-565+
+10d+=+440+
+d+=+44+
and
(1) +5n+%2B+10%2A44+=+565+
(1) +5n+=+565+-+440+
(1) +5n+=+125+
+n+=+25+
He has 44 dimes
check:
(2) +5%2A%2825%2B8%29+%2B+10%2A%282%2A44%29+=+1045+
+165+%2B+880+=+1045+
+1045+=+1045+
OK