Question

If x+1/x =7 find the value of x3+1/x3

Answer 1

$finding \: \: \: {x}^{3} + \frac{1}{ {x}^{3} } = ( {x + \frac{1}{x} })^{3} - 3(x + \frac{1}{x} ) \\ = {7}^{3} - 3 \times 7 \\ = 343 - 21 \\ = 322$