a) \(\Rightarrow x\left(x-1\right)+2\left(x-1\right)=0\)
\(\Rightarrow\left(x-1\right)\left(x+2\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=1\\x=-2\end{matrix}\right.\)
b) \(\Rightarrow5x\left(x-2021\right)-x+2022-1=0\)
\(\Rightarrow5x\left(x-2021\right)-x+2021=0\)
\(\Rightarrow5x\left(x-2021\right)-\left(x-2021\right)=0\)
\(\Rightarrow\left(x-2021\right)\left(5x-1\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=2021\\x=\dfrac{1}{5}\end{matrix}\right.\)
c) \(\Rightarrow2x\left(x-2\right)-\left(x-2\right)^2=0\)
\(\Rightarrow\left(x-2\right)\left(2x-x+2\right)=0\)
\(\Rightarrow\left(x-2\right)\left(x+2\right)=0\)
\(\Rightarrow\left[{}\begin{matrix}x=2\\x=-2\end{matrix}\right.\)
d) \(\Rightarrow81x^3=-3\)
\(\Rightarrow x^3=-\dfrac{3}{81}\)
\(\Rightarrow x^3=-\dfrac{1}{27}\)
\(\Rightarrow x=-\dfrac{1}{3}\)
\(a,\Rightarrow\left(x-1\right)\left(x+2\right)=0\\ \Rightarrow\left[{}\begin{matrix}x=1\\x=-2\end{matrix}\right.\\ b,\Rightarrow5x\left(x-2021\right)-x+2021=0\\ \Rightarrow\left(x-2021\right)\left(5x-1\right)=0\\ \Rightarrow\left[{}\begin{matrix}x=2021\\x=\dfrac{1}{5}\end{matrix}\right.\\ c,\Rightarrow2x\left(x-2\right)-\left(x-2\right)^2=0\\ \Rightarrow\left(x-2\right)\left(2x-x+2\right)=0\\ \Rightarrow\left[{}\begin{matrix}x=2\\x=-2\end{matrix}\right.\\ d,\Rightarrow x^3=-\dfrac{3}{81}=-\dfrac{1}{27}\Rightarrow x=-\dfrac{1}{3}\)
a)
\(x\left(x-1\right)+2\left(x-1\right)=0\)
(x+2)(x-1)=0
x+2=0 hoặc x-1=0
x=-2 hoặc x=1
b)
\(5x\left(x-2021\right)-x+2021+1-1=0\)
5x(x-2021)-(x-2021)=0
(5x-1)(x-2021)=0
5x-1=0 hoặc x-2021=0
x=1/5 hoặc x=2021
