SOLUTION: the cost of 4 pairs of shoes and 6 pairs of sneakers is $64. If the price of the shoes were increased by 10% and that of the sneakers by 5%, the total cost would be $69.80. find

Algebra ->  Expressions-with-variables -> SOLUTION: the cost of 4 pairs of shoes and 6 pairs of sneakers is $64. If the price of the shoes were increased by 10% and that of the sneakers by 5%, the total cost would be $69.80. find       Log On


   

Question 697602: the cost of 4 pairs of shoes and 6 pairs of sneakers is $64. If the price of the shoes were increased by 10% and that of the sneakers by 5%, the total cost would be $69.80. find the original price of a pair of shoes.
Answer by unlockmath(1688) About Me  (Show Source):
You can put this solution on YOUR website!
Hello,
Let's set up two equations with x represents the cost of shoes and y represents cost of sneakers:
4x+6y=64
[1.10(4x)+1.05(6y)=69.80]
Multiply the second equation by 100 to get:
110(4x)+105(6y)=6980
Expand this to:
440x+630y=6980
Now take the first equation multiply it by -110 to get:
-440x-660y=-7040
Add this equation to the second to get:
-30y=-60
Divide by -30 to get:
y=2
x=13
So a pair of shoes cost $13, pretty cheap, huh?
Make sense?
RJ
www.math-unlock.com