Question

9p²-?p+49

In order for the following expression to be a perfect square trinomial, fill in the missing number

Answer 1

Answer: ? = 42

Explanation:

(a-b)² = a² - 2ab + b². From 9p² -?p + 49 we see

9p² = (3p)² and 49 = 7² Then Middle term is -2·(3p)·7 = -42p