Rooftop Factoring

• 1. Factor out any GCF (Greatest Common Factor)

• 1. (6 )(6 )

• 2. Put the first number in front of both parentheses.

• 2. (6x )(6x )

• 3. Break down squared variable and put it in "front" or "back" as it should be.

• 3. (6)(-10) = -60

• 4. Multiply first and third numbers (rooftop) and list all factors of product.
• 5. If product is positive, find factors that add to middle term.

         If product is negative, find

          factors that subtract to middle

         term.

5.  (6x+4)(6x-15)

• 6. Put these factors in back of each

         set of parentheses.

6. 

• 7. Since 6 X 6 = 36 and our first number is 6, these are not the final answers. If there is a GCF for the terms in parentheses, divide by the GCF.

7.  (3x + 2)(2x - 5)

• 8. Check by multiplying first and last terms to see if the answer is correct.