Respuesta :

Answer:

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

Step-by-step 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)