Stephanie has 20 coins in her purse.
• Some are quarters.
• Some are dimes.
• The total value of the coins is $3.35.
How many of each type of coin does she have?


Answer :

Answer:

11 dimes and 9 quarters

Step-by-step explanation:

lets make x quarters and y dimes

Here is the equation we have so far:

x+y=20

BUT it can also be used to determine the values:

0.25x+0.10y=3.35

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0.25x+0.10y=3.35

x+y=20

Im going to solve for quarters first.

Multiply everything by 0.25 on the bottom equation: 0.25x+0.25y=5

Now you have two equations:

0.25x+0.10y=3.35

and 0.25x+0.25y=5

subtract out the 0.25x

.15y=1.65

y=11

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you have 11 dimes.

x+11=20

x=9

You have 9 quarters