Answer:
7 quarters and 3 dimes
Explanation:
We know that in total, Roy has 10 quarters and dimes all together.
Here are the variables I'll be using for my equations:
q = quarters
d = dimes
q + d = 10
We also know that the valve of the coins is 2.05.
0.25q + 0.1d = 2.05
To find one variable we need to only have one variable in the equation by using the "plug in" method.
But first we need to find what q equals with this method:
q + d = 10
-d -d
Properties of inequalities states we need to subtract d from both sides of the equation.
q = 10 -d
Use the "plug in" method to "plug" this into the second equation.
0.25( 10 -d ) + 0.1d = 2.05
Solve the equation. Here is my work shown:
2.5 - 0.25d + 0.1d = 2.05
2.5 - 0.15d = 2.05
-0.15d = -0.45
d = 3
We now know that Roy has 3 dimes. We can safely come to the conclusion that Roy has 7 quarters because it states that the total amount of quarters and dimes he has is 10.
I really hopes this helps you out.