The difference between 15 and the product of 5 and y

What is the order of magnitude for the number of liters in a large bottle of soda served at a party

Find the cosine function that is represented in the graph.

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).