Question

what are the factors of x^2-81?

Answer 1

add 81 to each sides and sqrt it

that gives you the roots

and the factors can be reconstructed from the roots if need be

Answer 2

x^2=81

x = +- 9

(x-9)(x+9)

Answer 3

= (x)^2 - (+-9)^2
=(x+9)(x-9) Ans