For this case we have the following quadratic functions:
Revenue: 
Cost: 
Then, we observe that the profit is given by the following mathematical relationship:

Substituting values we have:

Making the corresponding calculations we have:

Answer:
An expression that represents the profit is:

Answer:
The hot dog are $2.63
Step-by-step explanation:
Hot Dogs = H
Drinks = D
2H + 2D = 4
Divide both sides by 2
H + D = 2
Subtract D from either side
H = 2 -D
3H + D = 4.50
Plug in 2 - D for H
3(2- D ) + D = 4.50
6 - 3D + D = 4.50
6 - 4D = 4.50
Add 6 to either side
-4D = 10.50
Divide either side by -4
D = -2 . 625
Answer:
20/9
Step-by-step explanation:
Hope this helps!