Помогите пожалуйста 1,2,4.срочно надо

$1)\quad a)\; (3\sqrt{8} +\sqrt{18} +\sqrt{50} -2\sqrt{72} )\cdot \sqrt{2} =\\\\=3\sqrt{16}+\sqrt{36}+\sqrt{100}-2\sqrt{144}=3\cdot 4+6+10-2\cdot 12=4\\\\b)\; (3\sqrt2+\sqrt{50})\cdot \sqrt2=3\sqrt4+\sqrt{100}=3\cdot 2+10=16\\\\2)\quad \frac{1}{x-4} + \frac{24}{x^2-16} = \frac{x+1}{x+4} \; ,\; \; ODZ:\; x\ne \pm 4\\\\ \frac{1}{x-4} + \frac{24}{(x-4)(x+4)} - \frac{x+1}{x+4} =0\\\\ \frac{x+4+24-(x+1)(x-4)}{y} =0\;,\quad \frac{-x^2+4x+32}{(x-4)(x+4)} =0$

$\frac{-(x+4)(x-8)}{(x-4)(x+4)} =0\; ,$ $\frac{x-8}{x-4} =0$

$x=8$

$3)\\P=2(a+b)=25\\\\S=ab=34\\\\ \left \{ {{a+b=12,5} \atop {b=\frac{34}{a}}} \right. \left \{ {{a+\frac{34}{a}-12,5=02} \atop {b=\frac{34}{a}}} \right. \left \{ {{\frac{a^2-12,5a+34}{a}=0} \atop {b=\frac{34}{a}}} \right. \left \{ {{a_1=4;a_2=8,5} \atop {b_1=8,5;b_2=4}} \right. \\\\Otvet:(4;8,5);(8,5;4).$