Factoring – Difference of Two Squares a.k.a “DOTS” Make sure you always check for a GCF first! If you skip right to DOTS when there is a GCF, you will probably get the question wrong. After checking for a GCF, make sure the following are true: Are there only 2 terms? Is there a minus sign between the two terms (difference) Are both terms perfect squares? If all of these answers are yes, then it is time for DOTS

Factoring – Difference of Two Squares How to factor a Polynomial Using DOTS: Check for a GCF Make sure it is in fact DOTS Set up 2 ( ) Take the square root of each term, place in corresponding part of each ( ) If you want, you can multiply (Double Distribute/FOIL) to check your answer x2 – 16

Factoring – Difference of Two Squares Practice Examples: y2 – 9 4b2 – 25 25a2 – 16 36m2 – 49p2 x2 + 25 4x2 - 100