<PRE><B>Question 947327</B>
If I have a total of 30 dimes and quarters and the total value of the coins is $5.70, how many quarters do I have? How many dimes do I have? 

I am supposed to solve this using Systems of Linear Equations (the elimination method.)

I have written the equations out and know that they should be as follows:

d=dimes and q = quarters

30 = d + q and 5.70 = 0.10d and 0.25q
:
lets rewrite the equation that you have:
  d + q = 30
.10d + .25q = 5.70
Multiply the 2nd equation by 10, this makes .10 = 1
d + q = 30
d + 2.5q = 57
---------------subtraction eliminates d, find q
0 - 1.5q = -27
q = -27/-1.5
q = 18 quarters
find d using the 1st equation
d + 18 = 30
d = 12 dimes
:
:
Check solution in the 2nd original equation
.10(12) + .25(18) = 
1.20 + 4.50 = 5.70
:
Did this help?
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