Factoring Difference of Two Squares
What Numbers are Perfect Squares? List the first 20 Perfect Squares 1 4 9 16 25 36 49 64 81 100 121 144 169 196 225 256 289 324 361 400
Factoring: Difference of Two Squares Count the number of terms. Is it a binomial? Is the first term a perfect square? Is the last term a perfect square? Is it, or could it be, a subtraction of two perfect squares? x2 – 9 = (x + 3)(x – 3) The sum of squares will not factor a2 + b2
Using FOIL we find the product of two binomials.
Rewrite the polynomial as the product of a sum and a difference.
Conditions for Difference of Squares Must be a binomial with subtraction. First term must be a perfect square. (x)(x) = x2 Second term must be a perfect square (6)(6) = 36
Check for GCF. Sometimes it is necessary to remove the GCF before it can be factored more completely.
Removing a GCF of -1. In some cases removing a GCF of negative one will result in the difference of squares. Alternate Method Now you can use algebra to show that they are equivalent
Difference of Two Squares You Try
Factoring - Difference of Squares