How do you factor x squared minus 1? - Answers

x2 - 1 = (x + 1)(x - 1) This comes from a formula that is called "The Difference of Squares." The formula says that when you are subtracting two square numbers from each other that they can always be factored as such: a2 - b2 = (a + b)(a - b) Another example would be to factor x2 - 9. We could rewrite x2 - 9 as x2 - 32 which when we compare it to the formula above helps us to see that a=x and b=3. This yields the result: a2 - b2=(a + b)(a - b) x2 - 32 = (x + 3)(x - 3) And just for good measure here is another example :) Factor the following polynomial expression: x2 - 64 Step 1: Rewrite it as the difference of two squares: x2 - 82 Step 2: Plug in a=x and b=8 into the formula above to get: (x + 4)(x - 4)