Respuesta :

wegnerkolmp2741o

Answer:

x^2 -81

Step-by-step explanation:

(x+9)(x-9)

FOIL

first x*x = x^2

outer -9x

inner 9x

last -9*9 = -81

Add them together

x^2 -9x+9x -81

Combine like terms

x^2 -81

paimonmoney

Answer: B

Step-by-step explanation:

Simply using (a-b)(a+b)=a^2-b^2.

Evaluate the power (9^2).

x^2 - 81