Factor [tex]x^2-81[/tex] by using the difference of two squares.
[tex]x^2-y^2=(x+y)(x-y)[/tex]
Our x is x
Our y is 9 (As y² = 81, therefore a single y would be 9)
[tex](x+9)(x-9)[/tex]
Thus, the final answer is (x+9)(x-9)
