Which method is best to factor f(x) = x^2 - 81?

Use the difference of perfect squares

f(x) = x^2 - 81

f^2 - 81 = (f x -9), (f x 9)

f(f) = f^2 , f(-9) = -9f , f(9) = 9f , -9(9) = -81

(f(-9)), (f(9)) is your factors

hope this helps

135 is your answer

step-by-step explanation:

try 180 times three then divide that number by 4 (sides) to get your answer. im glad to : )

or