\(\dfrac{2x+1}{-27}=\dfrac{-3}{2x+1}\)

\(\Leftrightarrow\left(2x+1\right)\left(2x+1\right)=\left(-3\right)\left(-27\right)\)

\(\Leftrightarrow\left(2x+1\right)^2=81\)

\(\Leftrightarrow\left[{}\begin{matrix}2x+1=9\\2x+1=-9\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=4\\x=-5\end{matrix}\right.\)

\(\left(2x-3\right)\left(\dfrac{5}{4}x-6\right)=0\)

\(\Rightarrow2x-3=0\) hoặc \(\dfrac{5}{4}x-6=0\)

\(\Rightarrow x=\dfrac{3}{2}\) và \(x=\dfrac{24}{5}\)

\(\dfrac{72.100}{60}\text{%}=120\%\)

\(2019\left(2020-164\right)-2020\left(2019-164\right)\)

\(\Leftrightarrow\left(2019.2020-2019.164\right)-\left(2020.2019-2020.164\right)\)

\(\Leftrightarrow2019.2020-2019.164-2020.2019+2020.164\)

\(\Leftrightarrow\left(2019.2020-2020.2019\right)-\left(2019.164-2020.164\right)\)

\(\Leftrightarrow2020.164-2019.164\)

\(\Leftrightarrow164\left(2020-2019\right)\)

\(\Leftrightarrow164.1=164\)