Two groups of people entered a Drive-In restaurant. The first group ordered 6
hamburgers and 5 orders of French fries, and paid $4.55. The second group ordered 10
hamburgers and 6 orders of French fries and paid $7.00. How much would you have to
pay for one hamburger and one order of French fries?

Respuesta :

So here is how we are going to answer the problem above:
Given that f is the cost of French fries and b is the cost of Hamburger.
So: 5f + 6b = 4.55
5f = 4.55 - 6b (multiply both sides by 6) and we get
30f = 27.3 - 36b

Next,
6f + 10b = 7.00 (multiply both sides by 5) and we get
30f + 50b = 35 (Now substitute the value of 30f)
27.3 - 36b + 50b = 35
14b = 35 - 27.3
14b = 7.7 (divide both sides by 14)
b = 0.55

Therefore, the cost per hamburger is $0.55

Now go back to the cost of fries:
30f = 27.3 - 36b
30f = 27.3 - 36(0.55)
30f = 27.3 - 19.8
30f = 7.5 (divide both sides by 30)
f = 0.25
Therefore, the cost per french fries is $0.25
Hope this helps.