SOLUTION: I will like to know how i can solve the following word problem using two linear equations containing two unknowns. Paul has 40 dimes and quarters worth $8.50. How many of each co

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Question 721508: I will like to know how i can solve the following word problem using two linear equations containing two unknowns.
Paul has 40 dimes and quarters worth $8.50. How many of each coin does he have?
Found 2 solutions by mananth, ajones305:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
dimes -----x
quarters --------y
x+y =40..............(1)
10x+25y=850...........(2)
multiply (1) by -10 and add this equation to (2)
-10x-10y=-400
15y=450
y= 30
so x=10
dimes -----x----------10
quarters --------y-----30

Answer by ajones305(5) About Me  (Show Source):
You can put this solution on YOUR website!
Start with these equations:
Let x=the #of quarters Let y=the number of dimes.
X+Y=40
.10X+.25Y=8.50
(The values are .10 and .25 because a dime is equivalent to .10 of a dollar and a quarter is .25 of a dollar)
Now, solve by substitution!
X+Y=40--->Y=40-X
Then, substitute the Y value into the other equation.
.10X+.25(40-X)=8.50
.10X+10-.25X=8.50
Combine Like Terms
10-0.15X=8.50
Bring the 10 over to the other side.
-0.15X=-2.50
Divide both sides by -0.15
Find your answer from there. I led you most of the way, now it is your turn to think. Good luck! If you still need help, email me. :)