Question

найди множество натуральных решений неравенств 5/y<5/7

Answer 1

$\frac{5}{y}<\frac{5}{7}|:5\\\\\frac{1}{y}<\frac{1}{7}\\\\\frac{1}{y}-\frac{1}{7}<0\\\\\frac{7-y}{7y}<0$

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$x\in (7;+\infty)$