344: Factor by Grouping Lesson

Unit 9 Day 3 - Factor by Grouping

I can factor a polynomial with 4 terms by grouping.

Factoring by Grouping

• You know you should factor by grouping if you have 4 terms that cannot be combind

• Your first step should ALWAYS be to factor out the GCF of the polynomial

Example 1 $4n^3+8n^2-5n-10$ 

• Check for GCF

• Draw a box

• Find the GCF of each column and each row

• Check your answer by multiplying the rows and the columns.

• Write your final answer as a product of two binomials.

Example 2 $9c^3-12c^2+18c-24$ 

• Check for GCF

• Draw a box

• Find the GCF of each column and each row

• Check your answer by multiplying the rows and the columns.

• Write your final answer as a product of two binomials.

Multiple Choice

 $7r^3-8r^2+42r-48$  

•  $(r^2+6)(7r+8)$  

•  $(r^2+6)(7r-8)$  
  

•  $(r^2+6)(r2+8)$  
  

•  $(r^2+6)(7r+6)$  
  

Multiple Choice

 $5n^3-10n^2+3n-6$  

•  $\left(5n^2+3\right)\left(n-2\right)$  

•  $\left(5n^2-3\right)\left(n-2\right)$  

•  $\left(5n^3+3\right)\left(n-2\right)$  

•   $10n\left(n^2-6\right)$  

Multiple Choice

 $4p^3+8p^2+3p+6$  

•  $\left(2p^2+3\right)\left(p+2\right)$  

•   $\left(2p^2+6\right)\left(p+4\right)$  

•  $\left(4p^2+3\right)\left(p+2\right)$  

•   $\left(4p^2+8p\right)\left(3p+6\right)$  

Multiple Choice

 $20x^3-25x^2+4x-5$ 

•  $(5x^2-5)(4x+1)$  
  

•  $5(x^2-1)(4x+5)$  
  

•  $(5x^2+1)(4x-5)$  
  

•  $(5x^2+1)(4x-1)$  
  

Multiple Choice

 $30x^3+15x^2-18x-9$  

•  $(5x^2-3)(6x+1)$  
  

•  $(5x^2-3)(6x+3)$  
  

•  $3(5x^2+3)(2x-1)$  
  

•  $3(5x^2-3)(2x+1)$