Answer:

Step-by-step explanation:
The function

gives the mass of the car as a function of the number of passengers in it.
And the function

gives the potential energy of the car as a function of the car's mass.
Now if the height of the ramp is 30 meters, we have


And to find the potential energy as a function of the number of passengers, we just substitute
into
to get:


which gives the potential energy as a function of the number of passengers.
$10.8 rounding it to the nearest dollar is $10
The problem deals with a division and the rest of it, that is dividing the total amount of pencils into 9 classrooms and the rest, lets express it as fraction:
935/9 = 103 + 8/9
that is, if we multiply 103*9 we get 927 and are 8 pencils left over, therefore, 8 pencils are donated to the library and each classroom gets 103 pencils, in total 935 pencils are donated.