Day 110 – February 20

Algebra: Chapter 6, Lesson 6, page 281.

Factoring by Grouping

Factoring by grouping works for polynomials that are greater than trinomials. Grouping usually works with polynomials that have 4 terms. All that you have to do is group the polynomials into binomials using parentheses. But, remember, that not all 4 term expressions can be factored this way.

Example: ${\displaystyle 6x^3+9x^2+4x+6}$ becomes ${\displaystyle (6x^3+9x^2)+(4x+6)}$.

We can factor out a ${\displaystyle 3x^2}$ from the first binomial and a ${\displaystyle 2}$ from the second binomial leaving us with ${\displaystyle \left(3x^2\right)(2x+3)+2(2x+3)}$ or factoring out the ${\displaystyle (2x+3)}$, we have${\displaystyle (2x+3)(3x^2+2)}$.

Here is a link from purplemath.com. She calls it factoring in “pairs”.