Practicing Success
If \(\frac{7(x^2+1)-17x}{7x}\) = 2 then, \( { \left(\frac{x+1}{\sqrt {x }}\right) }^{2} \) = ? |
6.42 6.53 6.49 5 |
6.42 |
7(x2 + 1) - 17x = 14x 7(x2 + 1) = 14x + 17x 7(x2 + 1) = 31 x x2 + 1 = \(\frac{31}{7}\)x x + \(\frac{1}{x} = \frac{31}{7}\) [If x + \(\frac{1}{x}\) = a, then \(\sqrt {x } + \frac{1}{\sqrt {x }} \) = \(\sqrt {a + 2}\)] Therefore, \(\sqrt {x } + \frac{1}{\sqrt {x }} \) =\(\sqrt { \frac{31}{7}+2}\) = \(\sqrt { \frac{45}{7}}\) \( { \left(\sqrt {x } + \frac{1}{\sqrt {x }}\right) }^{2} \) = \(\frac{45}{7}\) \( { \left(\sqrt {x } + \frac{1}{\sqrt {x }}\right) }^{2} \) = 6.42 ⇒ \( { \left(\frac{x+1}{\sqrt {x }}\right) }^{2} \) = 6.42 |