Answers

2015-07-23T18:26:44+05:30
a^2+ \frac{9}{a^2}=31\\ \\ \Rightarrow a^2+ \frac{9}{a^2}-6=31-6\\ \\ \Rightarrow (a)^2+ (\frac{3}{a})^2-2 \times a \times  \frac{3}{a} =25\\ \\ \Rightarrow (a- \frac{3}{a})^2 =25\\ \\ \Rightarrow a- \frac{3}{a}= \pm \sqrt{25} = \pm 5

Value of a-(3/a) can be 5 or -5.
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