Question

What is the factored form of the expression?

16b^2 – 81

Answer 1

(4b-9) (4b+9)

Explanation:

16b^2 – 81

This is the difference of squares

(a^2 -c^2) = (a-c) (a+c)

a^2 = 16b^2 so a= 4b

c^2 = 81 so c = 9

(16b^2 – 81) = (4b-9) (4b+9)