SOLUTION: 4 small cheeseburgers & 3 orders of fries cost $11.45. Cost of 2 small cheeseburgers and 1 order of fries is $5.13. Set up a system of linear equations and solve to find the cost o

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: 4 small cheeseburgers & 3 orders of fries cost $11.45. Cost of 2 small cheeseburgers and 1 order of fries is $5.13. Set up a system of linear equations and solve to find the cost o      Log On


   

Question 4713: 4 small cheeseburgers & 3 orders of fries cost $11.45. Cost of 2 small cheeseburgers and 1 order of fries is $5.13. Set up a system of linear equations and solve to find the cost of each item.
Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
Let x = number of cheeseburgers
y = number of orders of fries

4x + 3y = 11.45
2x + y = 5.13

Multiply each side of the second equation by -3:
4x + 3y = 11.45
-6x - 3y = -15.39

-2x = -3.94

Divide each side by -2,
x+=+-3.94%2F-2 = $1.97

Substitute into the second equation:
2x + y = 5.13
2(1.97) + y = 5.13
3.94 + y = 5.13

Subtract 1.94 from each side:
3.94 -3.94 + y = 5.13 - 3.94
y = $1.19

Check in first equation:
4x + 3y = 11.45
4(1.97) + 3(1.19) = 11.45
7.88 + 3.57 =$11.45

Cheeseburger = $1.97
Fries = $1.19

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