Question

решите систему неравенств:
x² - 5x + 7 > 0
x²≤81​

Answer 1

Ответ:

$\left\{\begin{array}{l}x^2-5x+7>0\\x^2\leq 81\end{array}\right\ \ \left\{\begin{array}{l}x\in R\\x^2-81\leq 0\end{array}\right\ \ \left\{\begin{array}{l}x\in R\\(x-9)(x+9)\leq 0\end{array}\right\\\\\\\left\{\begin{array}{l}x\in R\\x\in [-9\ ;\ 9\ ]\end{array}\right\ \ \ \ \ Otvet:\ \ x\in [-9\ ;\ 9\ ]\ .\\\\\\P.S.\ \ \ R=(-\infty ;+\infty )$