The hourly rate is 60, so multiply 60 by the number of hours (h) and add the fee:
Answer: 60h + 35
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

3x-9=2x+4
3x-9+9=2x+4+9
3x=2x+13
3x-2x=2x-2x+13
x=13
Check:
3(13)-9=2(13)+4
39-9=26+4
30=30
The answer is "alternate exterior angles theorem."