SOLUTION: I have 14 coins equaling $2.10. I only have quarters and nickels. How many do j have of each?

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Question 961167: I have 14 coins equaling $2.10. I only have quarters and nickels. How many do j have of each?
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
Q=quarters; N=nickels
Q+N=14
Q=14-N Use this to substitute for Q
$0.25Q+$0.05N=$2.10 This converts number of quarters and nickels to dollars.
$0.25(14-N)+$0.05N=$2.10 This substitutes for Q (from above) to leave one variable.
$3.50-$0.25N+$0.05N=$2.10 Subtract #3.50 from each side.
-$0.20N=-$1.40 Divide each side by -$0.20
N=7 ANSWER 1:There are 7 nickels
Q=14-N=14-7=7 ANSWER 2: There are 7 quarters.
CHECK:
$0.25Q+$0.05N=$2.10
$0.25(7)+$0.05(7)=$2.10
$1.75+$0.35=$2.10
$2.10=$2.10