how do you factor a polynomial

Question

I am having trouble finding out how to do this. i just want a refresher.

Answer 1

Lets try a simple one...

 

     y=X^2+4x+4     to factor look at the last number

                               Ask yourself:   "What two numbers when multiplied

                               will give you four (last four) and when added will give

                               you the middle four. And when two -X's are multiplied

                                will give you an X-squared.  thus giving:

 

         y=(X+2)^2      y=(Xplus 2) squared                                                 

 

 

 

                   (X+2)

                   (X+2)       This way also works

                X^2             X times X= X^2

                +2x             x times 2                    

                +2x             X times 2                   

                2x2 =4           thus giving                 

 

      X^2 +4x +4

 

                                        The other way is called the FOIL   Method

Foil stands for:

F=First  (The X timesX)  =X^2

O=outer (2XX) Two times X

I=Inner  (2xX) Two times X

L=Last    2x2=4              

                                      Giving:  X^2 +4x +4                                       

 

The last way (only if you have to is the   Quadradic Formula:

                                                                                           y= (-b+-(sqrt b^2-4*A*C

                                                                                                ___________________

                                                                                                            2*A                     

Hope this helps