Quantitative Aptitude Ques 273
Question: If $ x-\sqrt{3}-\sqrt{2}=0 $ and $ y-\sqrt{3}+\sqrt{2}=0, $ then value of $ (x^{3}-20\sqrt{2})-(y^{3}+2\sqrt{2}) $ is
Options:
A) 1
B) 3
C) 0
D) 2
Show Answer
Answer:
Correct Answer: C
Solution:
- $ x=\sqrt{3}+\sqrt{2} $ and $ y=\sqrt{3}-\sqrt{2} $
$ \therefore $ $ (x^{3}-20\sqrt{2})-(y^{3}+2\sqrt{2}) $ $ =[{{(\sqrt{3}+\sqrt{2})}^{3}}-20\sqrt{2}]-[{{(\sqrt{3}-\sqrt{2})}^{3}}+2\sqrt{2}] $ $ =(3\sqrt{3}+2\sqrt{2}+9\sqrt{2}+6\sqrt{3}-20\sqrt{2})- $ $ (3\sqrt{3}-2\sqrt{2}-9\sqrt{2}+6\sqrt{3}+2\sqrt{2}) $ $ =(9\sqrt{3}-9\sqrt{2})-(9\sqrt{3}-9\sqrt{2})=0 $
BETA
