Respuesta :

Answer:

(2x - 9)(2x + 9)

Step-by-step explanation:

4x^2 - 81 = (2x - 9)(2x + 9)

Answer:

(2x+9)(2x-9)

Step-by-step explanation:

kind of simple actually

4x^2-81=(2x+9)(2x-9)