Question

помогите с алгеброй!!!!!!!​

Answer 1

$2\sqrt{5x+2}+3\sqrt{7-x}\\\left\{\begin{matrix}5x+2\geq 0\\ 7-x\geq 0\end{matrix}\right.\Leftrightarrow \left\{\begin{matrix}x\geq -\frac{2}{5}\\ x\leq 7\end{matrix}\right.\Rightarrow x\in \left [ -\frac{2}{5};7 \right ]$

$x^2=a-7\wedge x^2=3-2a\\\left.\begin{matrix}a-7<0\\ 3-2a<0\end{matrix}\right|\Rightarrow a\in \left ( \frac{3}{2};7 \right )$