A) 2.4
B) 3.2
C) 4
D) 5
Correct Answer: D
Solution :
\[\frac{\sqrt{x+4}+\sqrt{x-4}}{\sqrt{x+4}-\sqrt{x-4}}=\frac{2}{1}\] By componendo and dividendo, we get \[\frac{2\sqrt{x+4}}{2\sqrt{x-4}}=\frac{3}{1}\] On squaring, \[\frac{x+4}{x-4}=\frac{9}{1}\] \[\Rightarrow \] \[9x-36=x+4\]\[\Rightarrow \]\[8x=40\]\[\therefore \]\[x=5\]You need to login to perform this action.
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