Question

Heather and sarah families went to wendys for lunch,and each brought junior bacon cheeseburgers and fries.Heater' s family bought 6 junior bacon cheeseburgers and 4 orders of large fries,and the total before tax was 12.50.Sarah family only bought 3 junior bacon cheeseburgers,but 7 large orders of fries,and their total before tax was 13.70. How much did wendys charge for a junior bacon cheeseburger before tax?

Answer 1

`\$1.09`

Explanation:

All the costs mentioned here are before tax

Let cost of junior bacon cheese burger be
`x`

Cost of large fries be
`y`

Heather's order cost 12.50

`6x+4y=12.5\quad\ldots (i)`

Sarah's order cost 13.70

`3x+7y=13.7\quad\ldots (ii)`

Multiply
`(ii)` by
`2`

`6x+4y=12.5`

`6x+14y=27.4`

Subtracting the equations we get

`-10y=-14.9\\\Rightarrow y=(14.9)/(10)\\\Rightarrow y=1.49`

Cost of large fries is
`\$1.49`

`6x+4y=12.5\\\Rightarrow x=(12.5-4y)/(6)\\\Rightarrow x=(12.5-4* 1.49)/(6)\\\Rightarrow x=1.09`

Cost of junior bacon cheeseburger before tax is
`\$1.09`.