Advertisements

Question 1 : Factorize ( x 2 − 4 x − 5) ( x 2 − 4 x − 12) − 144


 

Question 1 : Factorize ( x 2 − 4 x − 5) ( x 2 − 4 x − 12) − 144

cross multiplication factorisation, difference of two squares factorisation, greatest common divisor factorisation, how to factorise 4 terms, factorisation method formula

Solution :

We write the given expression;

\[ (x^2-4x-5)(x^2-4x-12)-144 \]

We see that ​\( x^2-4x \)​ is present in first two multiplying terms, so for sake of simplicity we suppose it to be equale to y i-e

suppose ​\( y=x^2-4x \)

==> ​\( (y-5)(y-12)-144 \)

==>​\( =y^2-17y+60-144 \)

==>​\( =y^2-17y+84 \)

Dividing mid term into two parts such that their sum is (-17y) and their product is ​\( 84y^2 \)​. We can think of (-21y) and  (4y) — so;

==> ​\( =y^2 − 21y + 4y − 84 \)

==>​\( = y(y − 21) + 4(y − 21) \)

or

==> ​\( =[y(y − 21) + 4(y − 21)] \)

Taking (y-21) as common;

==>  ​\( =(y-21)(y+4) \)

Since we supposed ​\( y=x^2-4x \)

==> ​\( =(x^2-4x-21)(x^2-4x+4) \)

 

 

 


  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  
  •  

You may submit a MCQ or maths problem with solution tips here in the comment box below! If you could not solve anyone, you may submit a MCQ or maths problem without solution as well. We will try our level best to solve it for you!

Your email address will not be published.

You may use these <abbr title="HyperText Markup Language">HTML</abbr> tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

All original content on these pages is fingerprinted and certified by Digiprove
Insert math as
Block
Inline
Additional settings
Formula color
Text color
#333333
Type math using LaTeX
Preview
\({}\)
Nothing to preview
Insert