\(3,x^3-4x=0\)
\(x\left(x^2-4\right)=0\)
\(\left(x-2\right)x\left(x+2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=0\\x=2\end{matrix}\right.\)
\(4,4x-3\left(x-2\right)=7-x\)
\(4x-3x+6=7-x\)
\(x+6=7-x\)
\(2x=1\)
\(x=\dfrac{1}{2}\)
\(3\Leftrightarrow\left[{}\begin{matrix}x=0\\x=2\\x=-2\end{matrix}\right.\)
4 \(\Leftrightarrow4x-3x+6-7+x=0\Leftrightarrow x=\dfrac{1}{2}\)
3. \(x^3-4x=0\\ \Leftrightarrow x\left(x^2-4\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=2\end{matrix}\right.\)
Vậy PT có tập nghiệm là S= { 0 ; 2 }
4. \(4x-3\left(x-2\right)=7-x\\ \Leftrightarrow4x-3x+6=7-x\\ \Leftrightarrow4x-3x+x=7-6\\ \Leftrightarrow2x=1\\ \Leftrightarrow x=\dfrac{1}{2}\)
Vậy PT có tập nghiệm S = { \(\dfrac{1}{2}\) }
Bài 3:
\(\Leftrightarrow x.\left(x^2-4\right)=0\)
\(\Leftrightarrow x=0\) hay \(\Leftrightarrow\left(x-2\right)\left(x+2\right)=0\)
\(\Leftrightarrow x-2=0\) hoặc \(\Leftrightarrow x+2=0\)
\(\Leftrightarrow x=2\) \(\Leftrightarrow x=-2\)
Vậy S = \(\left\{0;2;-2\right\}\)
Bài 4:
\(\Leftrightarrow4x-3x+6=7-x\)
\(\Leftrightarrow x+x=7-6\)
\(\Leftrightarrow2x=1\\ \Leftrightarrow x=\dfrac{1}{2}\)
\(Vậy.S=\left\{\dfrac{1}{2}\right\}\)