Решите,пожалуйста.Подробно. 1. 2.

Решите задачу:

$1)\; \left \{ {{x\ \textless \ 8} \atop {9-x\ \textgreater \ 0}} \right. \; \left \{ {{x\ \textless \ 8} \atop {x\ \textless \ 9}} \right. \; \Rightarrow \; \; x\ \textless \ 8\\\\2)\; \left \{ {{7y+x^2=2} \atop {-x-y=2}} \right. \; \left \{ {{7(-x-2)+x^2=2} \atop {y=-x-2}} \right. \; \left \{ {{x^2-7x-16=0} \atop {y=-x-2}} \right. \\\\x^2-7x-16=0\\\\D=49+4\cdot 16=113\\\\x_1=\frac{7-\sqrt{113}}{2} \approx -1,8\; ;\; \; x_2\ \frac{7+\sqrt{113}}{2} \approx 8,8\\\\y_1=- \frac{7-\sqrt{113}}{2} -2= \frac{-7+\sqrt{113} -4}{2} = \frac{-11+\sqrt{113}}{2}$

$y_2=- \frac{7+\sqrt{113}}{2} -2= \frac{-7-\sqrt{113}-4}{2} = \frac{-11-\sqrt{113}}{2}$