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Perfect Squares. 

 

 Perfect Squares is another way of factoring trinomials (3 terms). 

  

Perfect Square trinomial can be factored using this pattern. 

 

 a^2 + 2ab + b^2 = ( a + b)^2

 a^2 - 2ab + b^2 = ( a - b)^2 

                          

In perfect square , your first and last terms are perfect squares and so the middle term is the product of square roots of the first and last term multiplied by 2.  

 

For example; x^2 + 14x + 49 

 When you factor the equation above. You know that your answer must be in two brackets. 

 

        (          ) (         ) 

 

 

Here the since there is no number in front of the variable, it means the variable has a coefficient of 1. So now you would put the factors of 1x^2 in the two brackets.

 

  • Find the square root of the first and last number.  

  x^2 = x times x

 49=    7 times 7 

 

  • So now when you find the 2 numbers you put them in the brackets. 

 

        ( x+7) (x+ 7) 

 

  • Simply. 

 

        ( x+7) ^2 

 

  The trinomial that results from squaring a binomial is called a PERFECT SQUARE trinomial. 

 

 Example #2 4g^2 + 28g + 49

 

 

                         2g          x         7 = 14g x 2 = 28g           Which is your middle term. 

 

 

Solution: (2g + 7) ( 2g +7) 

 

 

 

Simply : (2g + 7) ^2

 

To check your answer simply expand the answer,

 

   (2g +7)^2

= (2g +7) (2g +7) 

= 4g^2 +14g +14g + 49

= 4g^2 +28 g +49 

 

So once you get the equation you started with, that means your answer is correct. 

 

 

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