Hot Dog Stand
Let
C--------> total cost of the hot dog
x-------> is the number of toppings
we know that

where
The slope of the linear equation is equal to 
The y-coordinate of the y-intercept of the linear function is equal to 
That means -------> This is the cost of the hot dog without topping
Hamburgers Stand
Let
C--------> total cost of the hamburger
x-------> is the number of toppings
we know that

where
The slope of the linear equation is equal to 
The y-coordinate of the y-intercept of the linear function is equal to 
That means -------> This is the cost of the hamburger without topping
therefore
<u>the answer is</u>
The linear equation of the hamburger cost is equal to

Note: Consider the side of first triangle is TQ instead of TA.
Given:
Triangles TQM and TPN which share vertex T.

To find:
The theorem which shows that
.
Solution:
In triangle TQM and TPN,
[Given]
[Given]
[Given]
Since two sides and their including angle are congruent in both triangles, therefore both triangles are congruent by SAS postulate.
[SAS]
Therefore, the correct option is C.