SOLUTION: You have 24 coins (either dimes or quarters only) in your pockets that are worth 4.50 dollars. How many coins are quarters? How many coins are dimes?

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Question 811778: You have 24 coins (either dimes or quarters only) in your pockets that are worth 4.50 dollars. How many coins are quarters? How many coins are dimes?
Answer by erica65404(394) About Me  (Show Source):
You can put this solution on YOUR website!
dimes = x
quarters = y
24 coins are the number of dimes and number of quarters
x + y = 24
dimes are .10 and quarters are .25 and we want 4.50.
.10x + .25y = 4.50
now solve the first equation for y
x + y = 24
y = 24 - x
now use the substitution method to plug this into the other equation.
.10x + .25(24 - x) = 4.50
.10x + 6 - .25x = 4.50
-.15x = -1.50
x = 10
now plug this into the first equation
10 + y = 24
y = 14
We now know we have 10 dimes and 14 quarters.