SOLUTION: Eldora and finn went to an office supply store together. Eldora bought 15 boxes and paper clips and 7 packages of index cards for a total of $55.40.Finn bought 12 boxes of paper c

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Eldora and finn went to an office supply store together. Eldora bought 15 boxes and paper clips and 7 packages of index cards for a total of $55.40.Finn bought 12 boxes of paper c      Log On


   

Question 553250: Eldora and finn went to an office supply store together. Eldora bought 15 boxes and paper clips and 7 packages of index cards for a total of $55.40.Finn bought 12 boxes of paper clips and 10 packages of index cards for a total cost of $61.70 find the cost of one box of paper clips and the cost of one package of index cars
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
paper clips boxes $ x
Index card packets $ y 0

15 x + 7 y = 55.5 .............1
12 x + 10 y = 61.7 .............2
Eliminate y
multiply (1)by -10
Multiply (2) by 7
-150 x -70 y = -555
84 x 70 y = 431.9
Add the two equations
-66 x = -123.1
/ -66
x = 1.87
plug value of x in (1)
15 x + 7 y = 55.5
27.98 + 7 y = 55.5
7 y = 55.5-27.98
7 y = 27.52
y = 3.93
paper clips boxes $ 1 .87
Index card packets $ 3 .93
m.ananth@hotmail.ca