A) 0
B) 1
C) 5
D) \[\frac{1}{3}\]
Correct Answer: C
Solution :
\[\frac{1}{\sqrt{9}-\sqrt{8}}-\frac{1}{\sqrt{8}-\sqrt{7}}+\frac{1}{\sqrt{7}-\sqrt{6}}\] \[-\frac{1}{\sqrt{6}-\sqrt{5}}+\frac{1}{\sqrt{5}-\sqrt{4}}\] (or rationalization) \[=(\sqrt{9}+\sqrt{8})-(\sqrt{8}+\sqrt{7})+\sqrt{7}+\sqrt{6})\] \[-(\sqrt{6}+\sqrt{5})+(\sqrt{5}+\sqrt{4})\] \[=\sqrt{9}+\sqrt{4}=3+2=5\]You need to login to perform this action.
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