Срочно!!! 103 и 104, заранее спасибо

[latex] 1)\quad \frac{1}{n(n+1)} = \frac{1}{n} - \frac{1}{n+1} \; \; \; ili\; \; \; \frac{1}{(n-1)n} = \frac{1}{n-1} - \frac{1}{n} \\\\\frac{1}{(x-1)(x-2)} + \frac{1}{(x-2)(x-3)} +\frac{1}{(x-3)(x-4)} + \frac{1}{(x-4)(x-5)} =\\\\= \frac{1}{x-2} - \frac{1}{x-1} + \frac{1}{x-3} - \frac{1}{x-2}+ \frac{1}{x-4} - \frac{1}{x-3} + \frac{1}{x-5} - \frac{1}{x-4} =\\\\=- \frac{1}{x-1} + \frac{1}{x-5} = \frac{-(x-5)+(x+1)}{(x-1)(x-5)} = \frac{6}{(x-1)(x-5)} [/latex] [latex]2)\; \; \sqrt{12-6\sqrt3} + \sqrt{28+10\sqrt3} =\\\\= \sqrt{9+3-2\cdot 3\sqrt3} +\sqrt{25+3+2\cdot 5\sqrt3}=\\\\ \sqrt{(3-\sqrt3)^2} + \sqrt{(5+\sqrt3)^2} =|3-\sqrt3|+|5+\sqrt3|=\\\\=3-\sqrt3+5+\sqrt3=8[/latex] 8 - натуральное число