Factoring Quadratics Reteach

Factoring Quadratics Reteach

Objectives

1) Convert standard form of a quadratic to intercept form.

2) Use the linear factors to find x-intercepts.

The Two Forms

Standard Form

 $ax^2+bx+c$  
Intercept Form 
 $a\left(x-p\right)\left(x-q\right)$  Note: p and q are the x-intercepts 

Using Factoring to convert Standard Form to Intercept Form

Steps need:

1st- Identify a=___ b= ___ c=___
2nd- Set up the X
3rd- Use calculator to find factors
4th- Simplify factors if needed 
5th- Write in Intercept form

Multiple Choice

Identify a, b and c for, 

 $x^2-7x-18$ .

• a= 1 b =7 c=18

• a= 1 b= -7 c = -18

Multiple Choice

Which is the correct x-factor method set up for factoring

 $x^2-7x-18$  

Multiple Choice

What are the factors of -18 whose sum is -7?

• 2 and 9

• -2 and -9

• -2 and 9

• 2 and -9

Multiple Choice

What is the intercept form of

 $x^2-7x-18$ ?

•  $\left(x+2\right)\left(x+9\right)$  

•  $\left(x-2\right)\left(x-9\right)$  

•  $\left(x+2\right)\left(x-9\right)$  

•  $\left(x-2\right)\left(x+9\right)$  

Multiple Choice

Based on your previous answer, what are the x-intercepts for

 $x^2-7x-18?$  

• (2,0) and (9,0)

• (-2,0) and (-9,0) 

• (-2, 0) and (9,0) 

• (2,0) and (-9,0)

Multiple Choice

What is the intercept form of

 $x^2-5x-14?$  

•  $\left(x+2\right)\left(x-7\right)$  

•  $\left(x-2\right)\left(x+7\right)$  

Multiple Choice

Identify a, b and c for, 

 $2x^2+17x+21$ .

• a= 2 b =17 c=21

• a= 2 b= -17 c = -21

Multiple Choice

Which is the correct x-factor method set up for factoring

 $2x^2+17x+21$  

Multiple Choice

What are the factors of 42 whose sum is 17?

• 3 and 14

• -3 and -14

• -3 and 14

• 3 and -14

Multiple Choice

What is the intercept form of

 $2x^2+17x+21$ ?

•  $\left(x+3\right)\left(x+14\right)$  

•  $\left(x-3\right)\left(x-14\right)$  

•  $\left(2x+3\right)\left(x+7\right)$  

•  $\left(3x-2\right)\left(x+7\right)$  

Multiple Choice

Based on your previous answer, what are the x-intercepts for

 $2x^2+17x+21?$  

•  $\left(\frac{-3}{2},0\right)\ and\ \left(-7,0\right)$  
  

•  $\left(0,\frac{2}{3}\right)\ and\ \left(0,7\right)$  
  

•  $\left(3,0\right)\ and\ \left(14,0\right)\$  

•  $\left(0,3\right)\ and\ \left(0,14\right)\$  

Multiple Choice

What is the intercept form of

 $4x^2-7x-2?$  

•  $\left(4x+1\right)\left(x-2\right)$  

•  $\left(x-8\right)\left(x+1\right)$