Question

Answer 1

x > 2

x < -2

 

Answer 2

x > 2

x < -2

Answer 3

ĐKXĐ:
\(\left\{{}\begin{matrix}2-x\ne0\\x^2-4\ne0\\2+x\ne0\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}x\ne2\\x\ne-2\end{matrix}\right.\)

Answer 4

Để `A` xác định

`2-x\ne 0, x^2-4\ne 0, 2+x\ne 0, 4-x^2\ne 0`

`<=> x\ne 2, (x-2)(x+2)\ne 0, x\ne -2, (2-x)(2+x)\ne 0`

`<=> x\ne 2, x\ne -2`