Question

Tìm X: x(3x+1)+3x+1=0

Mn giúp mình nha

Answer 1

\(\Rightarrow\left(3x+1\right)\left(x+1\right)=0\\ \Rightarrow\left[{}\begin{matrix}3x+1=0\\x+1=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-\dfrac{1}{3}\\x=-1\end{matrix}\right.\)

Answer 2

x.(3x + 1) + 3x + 1 = 0

⇒ x.(3x + 1) + (3x + 1) =0

⇒ (x + 1).(3x + 1) =0

\(\Rightarrow\left[{}\begin{matrix}3x+1=0\\x+1=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}3x=-1\\x=-1\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=-\dfrac{1}{3}\\x=-1\end{matrix}\right.\)