Question

If x -(2/x)=3, then x^3(-8/x^3)
is equal to _?

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Answer 1

Answer:

- 8 is the ans

Step-by-step explanation:

27 + 8 /7 × -8/(2+8/27)

Answer 2

$\sf \: We \: know \: the \: formula,$

$\boxed{ \sf{ ( {x - \frac{1}{x} )}^{3} = {x}^{3} - \frac{1}{ {x}^{3} } - 3(x - \frac{1}{x} ) }}$

$\sf \: ( {x - \frac{2}{x}) }^{3} = {x}^{3} - \frac{8}{ {x}^{3} } - 3 (x - \frac{2}{x} ) \\ \\ \sf \: ( {3})^{3} \: = \: {x}^{3} - \frac{8}{ {x}^{3} } - 3(3) \\ \\ \sf \: 27 \: = \: {x}^{3} - \frac{8}{ {x}^{3} } - 9 \\ \\ \sf \: 27 + 9 \: = \: {x}^{3} - \frac{8}{ {x}^{3} } \\ \\ \boxed{ \red{\sf {\implies\: {x}^{3} - \frac{8}{ {x}^{3} } = 36}}}$