Quantitative Aptitude Ques 395
Question: $ {{(a^{2}+2a)}^{2}}+12,(a^{2}+2a)-45 $ can be expressed as
Options:
A) $ (a-1)(a-3)(a^{2}+2a+15) $
B) $ (a-1)(a+3)(a^{2}+2a+15) $
C) $ (a+1)(a+3)(a^{2}+2a+15) $
D) $ (a+1)(a-3)(a^{2}+2a+15) $
Show Answer
Answer:
Correct Answer: B
Solution:
- Given, $ {{(a^{2}+2a)}^{2}}+12,(a^{2}+2a)-45 $ Let $ (a^{2}+2a)=x $ Then, $ x^{2}+12x-45=x^{2}+15x-3x-45 $ $ =x,(x+15)-3,(x+15) $ $ =(x+15)(x-3) $ Now, putting the value of x in these factors. $ =(a^{2}+2a+15)(a^{2}+2a-3) $ $ =(a^{2}+3a-a-3)(a^{2}+2a+15) $ $ =[a,(a+3)-1,(a+3)(a^{2}+2a+15) $ $ =(a-1)(a+3)(a^{2}+2a+15) $
BETA
