a)\(2x^3=x^2+2x-1\Leftrightarrow2x^3-x^2-2x+1=0\Leftrightarrow x^2\left(2x-1\right)-\left(2x-1\right)=0\)
\(\Leftrightarrow\left(2x-1\right)\left(x^2-1\right)=0\Leftrightarrow\left(2x-1\right)\left(x-1\right)\left(x+1\right)=0\)
<=> 2x-1=0 hoặc x-1=0 hoặc x+1=0 <=> x=1/2 hoặc x=1 hoặc x=-1
b)\(x^2-4+\left(x-2\right)\left(3-2x\right)=0\Leftrightarrow\left(x-2\right)\left(x+2\right)+\left(x-2\right)\left(3-2x\right)=0\)
\(\Leftrightarrow\left(x-2\right)\left(x+2+3-2x\right)=0\Leftrightarrow\left(x-2\right)\left(5-x\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x-2=0\\5-x=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=2\\x=5\end{cases}}\)
b.\(\left(x-2\right)\left(x+2+3-2x\right)=0\) \(\Rightarrow\left(x-2\right).\left(-x+5\right)=0\) \(\Rightarrow\) \(\hept{\begin{cases}x=2\\x=5\end{cases}}\)