Đáp án:
b) \(\left\{ \begin{array}{l}
x \ne 1\\
y \ne - 2
\end{array} \right.\)
Giải thích các bước giải:
\(\begin{array}{l}
a)DK:\left\{ \begin{array}{l}
x \ge 0\\
y - 1 \ge 0
\end{array} \right.\\
\to \left\{ \begin{array}{l}
x \ge 0\\
y \ge 1
\end{array} \right.\\
b)DK:\left\{ \begin{array}{l}
x - 1 \ne 0\\
y + 2 \ne 0
\end{array} \right.\\
\to \left\{ \begin{array}{l}
x \ne 1\\
y \ne - 2
\end{array} \right.
\end{array}\)
