Question

First 9n eto ans step by step gets brainliest​

Answer 1

Answer:

${x}^{3} + \frac{1}{ {x}^{3} } = 4 \sqrt{7}$

Step-by-step explanation:

${x}^{2} + \frac{1}{ {x}^{2} } = 5 \\ \\ {x}^{2} + \frac{1}{ {x}^{2} } + 2 = 5 + 2 \\ \\ {(x + \frac{1}{x}) }^{2} = 7 \\ \\ x + \frac{1}{x} = \sqrt{7} \\ \\ {(x + \frac{1}{x} )}^{3} = {\sqrt{7} }^{3} \\ \\ \\ {x}^{3} + \frac{1}{ {x}^{ 3} } + 3(x + \frac{1}{x} ) = 7 \sqrt{7} \\ \\ {x}^{3} + \frac{1}{ {x}^{3} } + 3 \sqrt{7} = 7 \sqrt{7} \\ \\ {x}^{3} + \frac{1}{ {x}^{3} } = 4 \sqrt{7}$