Question: If the LCM and HCF of two expressions are $ (x^{2}+6x+8)(x+1) $ and $ (x+1) $ respectively and one of the expressions is $ x^{2}+3x+2, $ then find the other expression.
Options:
A) $ x^{2}+5x+4 $
B) $ x^{2}-5x+4 $
C) $ x^{2}+4x+5 $
D) $ x^{2}-4x+5 $
Show Answer
Answer:
Correct Answer: A
Solution:
- Given, $ LCM=(x^{2}+6x+8)(x+1) $
or $ (x+4)(x+2)(x+1) $
and $ HCF=\text{(}x+1) $
Ist expression $ =x^{2}+3x+2 $ or $ (x+1)(x+2) $
As we know that,
Product of two expressions $ LCM\times HCF $
$ \Rightarrow $ $ (x+1)(x+2)\times 2ndexpression $
$ =(x+4)(x+2)(x+1)(x+1) $
$ \therefore $ 2nd expression $ =\frac{(x+4)(x+2)(x+1)(x+1)}{(x+1)(x+2)} $
$ =(x+4)(x+1) $
$ =x^{2}+4x+x+4 $
$ =x^{2}+5x+4 $