If postage costs $.54 for the first ounce and $.22 for each additional ounce, calculate the cost of mailing a 10-ounce envelope.

Barbara deposited $300 in the bank. if the bank pays her simple interest at the rate of 4 percent per year, how much money will she have in her account at the end of 9 months?

Can somebody 1. what is the formula for finding the vertical distance between two points on a coordinate plane?

What is the area of a triangle with vertices at (-3 3) (-3,2) and (1,2)?