Question

Answer 1

D=R\(-3;3)

=>D=(-\(\infty\);-3]\(\cup\)[3;+\(\infty\))

C=[-1;4]

Do đó: \(C\cup D=(-\infty;-3]\cup[-1;+\infty)\)

\(E\subset\left(C\cup D\right)\)

=>\(\left[{}\begin{matrix}a-2>=-1\\a< =-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}a>=1\\a< =-3\end{matrix}\right.\)

Answer 2

\(C\cup D=(-\infty;-3]\cup[-1;+\infty)\)

\(E\subset\left(C\cup D\right)\Leftrightarrow\left[{}\begin{matrix}a-2\ge-1\\a\le-3\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}a\ge1\\a\le-3\end{matrix}\right.\)