Помогите ребят кто сделает

Решите задачу:

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