Given:
Charges for rental card = $10
Charges for movie = $2 per movie
To find:
The linear equation for given situation and find the cost to rent 6 movies.
Solution:
Let y be the total cost for x number of movies.
Cost of one movie = $2
Cost of x movies = $2x
Total cost = Charges for rental card + Charges for x movies

Put x=6 to find the cost of 6 movies.



Therefore, the total cost for a new customer to rent 6 movies is $22.
For a better understanding of the answer please find the diagram in the attachment.
As can be clearly seen from the diagram that the distance, "d" (shown in dark blue) of 100 feet which is covered on the sloped/inclined road is actually making an angle of only 30 degrees with the force of 200 pounds which is being applied on the road. That angle of 30 degrees is what matters.
So, the force, F=200 pounds
distance, d=100 feet
And the angle between the force, F and the distance, d is: 
Therefore, as per formula, the work, W, done will be:

This, when applied to the question we have will give us:

Its formula Is h^2=b^2+c^2
and it involves the perpendicular, the base and the hypotenuse of a right triangle only.
Usually in questions, one of the value is not given and we have to solve using the theorem to get the last value