a: \(\left(2x-3\right)^{2012}+\left(y-\dfrac{2}{5}\right)^{2014}+\left|x+y-z\right|=0\)
\(\Leftrightarrow\left\{{}\begin{matrix}2x-3=0\\y-\dfrac{2}{5}=0\\x+y-z=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{3}{2}\\y=\dfrac{2}{5}\\z=\dfrac{19}{10}\end{matrix}\right.\)
b: 2015-|x-2015|=x
=>|x-2015|=2015-x
=>x-2015<=0
hay x<=2015
d: |x-999|+|1998-2x|=0
=>x-999=0
hay x=999