Math, asked by tabassum10, 1 year ago

x+1/x=7,Find x^3+1/x^3

Answers

Answered by DaIncredible
3
Hey friend,
Here is the answer you were looking for:
x +  \frac{1}{x}  = 7 \\  \\ then \\  {( x + \frac{1}{x} )}^{3}  =  {(7)}^{3}  \\  \\ by \: using \: the \: formula \\  {(a + b)}^{3}  =  {a}^{3}  +  {b}^{3}  + 3ab(a + b) \\  \\   {x}^{3}  +  \frac{1}{ {x}^{3} }  + 3 \times x \times  \frac{1}{x} (x +  \frac{1}{x} ) = 343 \\  \\  {x}^{3}  +   \frac{1}{ {x}^{3} }  + 3(7) = 343 \\  \\  {x}^{3}  +   \frac{1}{ {x}^{3} }  = 343 - 21 \\  \\  {x}^{3}  +  \frac{1}{ {x}^{3} }  = 322

Hope this helps!!!

@Mahak24

Thanks...
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