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# algebra

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If x + 1/x = 3, then find x^4 + 1/x^4.

Feb 22, 2021

#1
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$$\frac{x+1}{x}=3$$

$$x+1=3x$$

$$1=2x$$

$$\frac{1}{2}=x$$ or $$x=\frac{1}{2}$$

so:

$$x^4 + \frac{1}{x^4}$$

$$(\frac{1}{2})^4 + (\frac{1}{(\frac{1}{2})^4})$$

$$0.0625+\frac{1}{0.0625}$$

$$16.0625$$