Question

Jim and Abby each bought burgers and fries from the concession stand at the fair. Jim bought 3 burgers and 2 orders of fries for $17. Abby bought 2 burgers and 4 orders of fries for $18.

Based on the information above, how much did the concession stand charge for each burger?

How much did it charge for each order of fries?

Answer 1

Burger = $4

Fries = $2.5

Explanation:

Let price of fries be f and price of burgers be b

We can write the first equation as:

`3b+2f=17`

and 2nd equation as:

`2b+4f=18`

Let's multiply the first equation by (-2), so we have:

`3b+2f=17---*[-2]\\-6b-4f=-34`

Now we add up this equation and 2nd equation and eliminate f and solve for b first:

`-6b-4f=-34\\2b+4f=18\\--------\\-4b=-16\\b=(-16)/(-4)\\b=4`

Now using b = 4 and putting in the first equation, we can solve for f:

`3b+2f=17\\3(4)+2f=17\\12+2f=17\\2f=17-12\\2f=5\\f=(5)/(2)\\f=2.5`

Hence, each burger costs $4 and each fries cost $2.5