Quantitative Aptitude Ques 1770
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.
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:
- LCM $ (x^{2}+6x+8)(x+1) $
or $ (x+4)(x+2)(x+1) $
HCF $ =(x+1) $
1st expression $ =x^{2}+3x+2 $
or $ (x+1)(x+2) $
As we know that,
Product of two expressions $ =LCM\times HCF $
$ (x+1)(x+2)\times $ IInd expression
$ =(x+4)(x+2)(x+1)(x+1) $
IInd 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 $