Question

Answer 1

a: ĐKXĐ: \(x^2+5x+4\ne0\)

=>\(\left(x+1\right)\left(x+4\right)\ne0\)

=>\(\left\{{}\begin{matrix}x+1\ne0\\x+4\ne0\end{matrix}\right.\)

=>\(x\notin\left\{-1;-4\right\}\)

Answer 2

a) Để phân thức \(M\) xác định thì:

\(x^2+5x+4\ne0\)

\(\Leftrightarrow\left(x+1\right)\left(x+4\right)\ne0\)

\(\Rightarrow x\ne-1;x\ne-4\)