Solve for n. (7subscript2)subscript4=n subscript 8​

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

Leonardo wrote an equation that has an infinite number of solutions. one of the terms in leonardo’s equation is missing, as shown below.

Sections of prefabricated woods are each 5 1/3 feet long, how long are 7 1/2 sections placed end to end?