Question

Determine the expression that shows a difference of perfect squares and factor it, showing work.

16x2 − 81
14x2− 49
9x2 + 100

Answer 1

Answer is 1st option

16x²-81

(4x)² - 9²

Thus it is the difference of squares of 4x and 9

Factorising (4x)² - 9² , we would get:

(4x + 9)(4x - 9)

As a² - b² = ( a + b)(a - b)