Question

помогите ребят кто сделает

Answer 1

$1)frac{1}{x {}^{2} - y {}^{2} } + frac{1}{(x - y) {}^{2} } \ frac{1}{(x - y)(x + y)} + frac{1}{(x - y) {}^{2} } \ frac{x - y + x + y}{(x + y)(x - y) {}^{2} } \ frac{2x}{(x + y)(x - y)(x - y)} \ frac{2 x}{(x {}^{2} - y {}^{2} )(x - y)} = frac{2x}{x {}^{3} - x {}^{2} y - xy {}^{2} + y {}^{ 3} } \ 2) frac{1}{a + b} + frac{1}{(a + b) {}^{2} } \ frac{(a + b) times 1}{(a + b)(a + b)} + frac{1}{(a + b) {}^{2} } \ frac{a + b}{(a + b) {}^{2} } + frac{1}{(a + b) {}^{2} } = frac{a + b + 1}{(a + b) {}^{2} } \ 3) frac{1}{x {}^{2} - 49} + frac{2}{x - 7} \ frac{1}{(x - 7)(x + 7)} + frac{2}{x - 7} \ frac{1 + 2(x + 7)}{(x - 7)(x + 7)} \ frac{1 + 2x + 14}{x {}^{2} - 49} = frac{15 + 2x}{x {}^{2} - 49} \ 4) frac{1}{(7 + a) {}^{2} } + frac{5}{49 - a {}^{2} } \ frac{1}{(7 + a) {}^{2} } + frac{5}{(7 - a)(7 + a)} \ frac{7 - a + 5(7 + a)}{(7 - a)(7 + a) {}^{2} } \ frac{7 - a + 35 + 5a}{(7 - a)(7 + a)(7 + a) } \ frac{42 + 4a}{(49 - a { }^{2} )(7 + a)} \ frac{42 + 4a}{343 + 49a - 7a {}^{2} - a {}^{3} }$