Question

СРОЧНО НАДО!! ПОМОГИТЕ ПОЖАЛУЙСТА!
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Answer 1

$\displaystyle\bf\\64x^{2} +\frac{1}{x^{2} } =65\\\\\\\Big(8x+\frac{1}{x} \Big)^{2} =\Big(8x\Big)^{2} +2\cdot 8x\cdot \frac{1}{x} +\Big(\frac{1}{x} \Big)^{2} =\\\\\\=64x^{2} +16+\frac{1}{x^{2} } =65+16=81\\\\\\\Big(8x+\frac{1}{x} \Big)^{2} =81\\\\\\8x+\frac{1}{x} =\sqrt{81}=9\\\\\\Otvet \ : \ 9$