Question

Answer 1

Câu 29: ĐKXĐ: \(\begin{cases}5-3\left|x\right|\ge0\\ x^2+4x+3<>0\end{cases}\Rightarrow\begin{cases}3\left|x\right|\le5\\ \left(x+1\right)\left(x+3\right)<>0\end{cases}\)

=>\(\begin{cases}\left|x\right|\le\frac53\\ x\notin\left\lbrace-1;-3\right\rbrace\end{cases}\Rightarrow\begin{cases}-\frac53\le x\le\frac53\\ x\notin\left\lbrace-1;-3\right\rbrace\end{cases}\Rightarrow\begin{cases}-\frac53\le x\le\frac53\\ x<>-1\end{cases}\)

=>Chọn C

Câu 24: ĐKXĐ: \(\sqrt[3]{x^2-3x+2}-\sqrt[3]{x^2-7}<>0\)

=>\(\sqrt[3]{x^2-3x+2}<>\sqrt[3]{x^2-7}\)

=>\(x^2-3x+2<>x^2-7\)

=>-3x<>-9

=>x<>3

=>Chọn A