Peform the multiplication of (x -1)(x + 1)

Question

(x-1)(x+1)

Answer 1

To find the solution the quickest way to use FOIL (First, Outside, Inside, Last).

 

(x-1)(x+1)= x*x + 1*x + (-1)*x + (-1)*1

 

(x-1)(x+1)= x² +x -x -1

(x-1)(x+1)= x² -1

Answer 2

You can also recognize this is a difference in perfect squares.

 

(a - b)(a + b) = a² - b²

 

 

Applying this to the expression.

 

(x - 1)(x + 1) = x² - 1