Finding the Right Place for the Fulcrum

    23) If a lever were 12 feet long, with 75 pounds on one end and
45 pounds on the other, where would the fulcrum have to be placed
to balance it?

        75 * x = 45(12-x)

        75x = 540 -45x

        120x = 540

        x = 4.5

    The fulcrum would have to be placed 4.5 feet to the right of the
75 pound weight in order to have balance.  (The 45-pound weight,
therefore, will be 7.5 feet from the fulcrum.)

    We can also look at this in the following way to double-check
our answer:

        75 (lbs) * 4.5 (feet from the fulcrum) = 7.5 (feet from 
   the fulcrum) * 45 (lbs)

        337.5 = 337.5