Question

Помогите с первый вариантом

Answer 1

1.
$= \frac{3y \times 3 - 5x \times 2}{15x {}^{2} y {}^{2} } = \frac{9y - 10x}{15 {x}^{2} {y}^{2} }$
2.
$= \frac{4}{(y - 2)(y + 2)} - \frac{1}{y - 2} = \\ = \frac{4 - (y + 2)}{(y - 2)(y + 2)} = \\ = \frac{4 - y - 2}{ (y - 2)(y + 2) } = \\ = \frac{2 - y}{(y - 2)(y + 2) } = \\ = \frac{ - (y - 2)}{(y - 2)(y + 2) } = \\ = - \frac{1}{y + 2}$
3.
$= - \frac{2}{a + b} + \frac{3a + 3b}{(a + b)^{2} } = \\ = \frac{3a + 3b - 2(a + b)}{(a + b)^{2}} = \\ = \frac{3a + 3b - 2a - 2b}{(a + b)^{2}} = \\ = \frac{a + b }{(a + b)^{2}} = \\ = \frac{1}{a + b}$
4.
$= \frac{6}{5(a - 2)} - \frac{2}{3(a - 2)} = \\ = \frac{3 \times 6 - 2 \times 5}{15(a - 2)} = \frac{18 - 10}{15(a - 2)} = \\ = \frac{8}{15a - 30}$
5.
$= \frac{1}{x(x - y)} - \frac{1}{y(x - y)} = \\ = \frac{y - x}{xy(x - y)} = \\ = \frac{ - (x - y)}{xy(x - y)} = \\ = - \frac{1}{xy}$