Bài 1:
a: \(2x^2-5x+3=0\)
=>\(2x^2-2x-3x+3=0\)
=>\(2x\left(x-1\right)-3\left(x-1\right)=0\)
=>(x-1)(2x-3)=0
=>\(\left[{}\begin{matrix}x-1=0\\2x-3=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=\dfrac{3}{2}\end{matrix}\right.\)
b: \(x^3-3x^2-4x+12=0\)
=>\(\left(x^3-3x^2\right)-\left(4x-12\right)=0\)
=>\(x^2\left(x-3\right)-4\left(x-3\right)=0\)
=>\(\left(x-3\right)\left(x^2-4\right)=0\)
=>(x-3)(x-2)(x+2)=0
=>\(\left[{}\begin{matrix}x-3=0\\x-2=0\\x+2=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=2\\x=-2\end{matrix}\right.\)
c: \(x\left(x-5\right)=6\)
=>\(x^2-5x=6\)
=>\(x^2-5x-6=0\)
=>\(x^2-6x+x-6=0\)
=>\(x\left(x-6\right)+\left(x-6\right)=0\)
=>(x-6)(x+1)=0
=>\(\left[{}\begin{matrix}x-6=0\\x+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=6\\x=-1\end{matrix}\right.\)
