Question 1170904: At a local store, Kelly and Martin bought some notebooks and pencils. Kelly bought 4 notebooks and 25 pencils for $16.71. Martin bought 6 notebooks and 20 pencils for $21.74. What is the cost of 1 notebook and 5 pencils?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! At a local store, Kelly and Martin bought some notebooks and pencils.
Kelly bought 4 notebooks and 25 pencils for $16.71.
4n + 25p = 16.71
Martin bought 6 notebooks and 20 pencils for $21.74.
6n + 20p = 21.74
:
multiply the 1st equation by 3, the 2nd equation by 2
12n + 75p = 50.13
12n + 40p = 43.48
--------------------Subtraction eliminates n, find p
0 + 35p = 6.65
p = 6.65/35
p = $.19 for each pencil
:
Use the 1st original equation to find n
4n + 25(.19) = 16.71
4n = 16.71 - 4.75
4n = 11.96
n = 11.96/4
n = $2.99 for each note book
:
Check solutions in the 2nd original equation
6(2.99) + 20(.19) =
17.94 + 3.80 = 21.74
:
What is the cost of 1 notebook and 5 pencils?
2.99 + 5(.19) = $3.94
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