Question

Упростите выражение:​

Answer 1

Ответ:

а

$\frac{x - y}{x} - \frac{5y}{ {x}^{2} } \times \frac{ {x}^{2} - xy }{5y} = \frac{x - y}{x} - \frac{5y}{ {x}^{2} } \times \frac{x(x - y)}{5y} = \\ = \frac{x - y}{x} - \frac{x - y}{x} = 0$

б

$( \frac{a}{b {}^{2} - ab} + \frac{b}{a {}^{2} - ab} ) \times \frac{ab}{b - a} = \\ = ( \frac{a}{b(b - a)} + \frac{b}{a(a - b)} ) \times \frac{ab}{b - a} = \\ = \frac{a}{b(b - a)} - \frac{b}{a(b - a)} ) \times \frac{ab}{b - a} = \\ = \frac{a {}^{2} - b {}^{2} }{ab(b - a)} \times \frac{ab}{b - a} = \frac{(a - b)(a + b)}{(b - a) {}^{2} } = \frac{ a + b}{a - b}$