Factoring Quadratics December 1st, 2016

Review: Multiplying Binomials Ex. 1: Multiply and simplify.

Factoring is just the reverse of multiplying these binomials *Factoring is just the reverse of multiplying these binomials. The binomials (2x+3) and (3x-1) are called the factors of the expression . We can break the expression back down into factors by guess-and-checking or by using a number of other strategies.

X-Box Method *One strategy for factoring an expression of the form is called the x-box method. Step 1: Make a big X and place the coefficients in the top space and in the bottom space, as shown.

Step 2: Fill the other spaces with two numbers m and n that multiply to get but add to get . For example, in and , so use the numbers 9 and -2, since and (m) (n)

Step 3: Now use your area model to input the numbers like this. Then place the common factors of each row or column on the outside to complete your area model in reverse.

*There you have it.

Ex. 2: Factor each expression. (b) (c) (d)