A= bh/2

a' = b'h/2 + bh'/2

b' = (a' - bh'/2)(2/h) can someone explain this. its steps to the derivative of bh/2.

Abox contains 1 plain pencil and 4 pens. a second box contains 5 color pencils and 5 crayons. one item from each box is chosen at random. what is the probability that a plain pencil from the first box and a color pencil from the second box are selected? write your answer as a fraction in simplest form.

Angela took a general public aptitude test and scored in the 88th percentile for aptitude in accounting. what percentage of the scores were at or below her score?

Which equation is y = -6x2 + 3x + 2 rewritten in vertex form?