Solution
$$(\sqrt x + \frac{1}{\sqrt x}) ^ 2$$ = x + $$\frac{1}{x}$$ + 2 = 7
x + $$\frac{1}{x}$$ = 5
$$( x + \frac{1}{ x}) ^ 3$$ = $$x^3 + \frac{1}{ x}^3$$ + 3 * x * $$\frac{1}{x}$$ (x + $$\frac{1}{x}$$)
125 = $$x^3 + \frac{1}{x^3}$$ + 15
$$x^3 + \frac{1}{x^3}$$ =110
So , the answer would be option a)110.
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