Question

how do you simplify (x²-1)

Answer 1

(x+1)(x-1)

Answer 2

This is a differnce of squares: a^2-b^2=(a-b)(a+b)

Answer 3

thanks

Answer 4

You must be careful. If you are given a question like,
$$\frac{x^2-1}{x+1}=\frac{(x-1)(x+1)}{x+1}=x - 1$$
For in this case you must stipulate that $$x+1\ne 0$$ so that you can actually do this simplification.