a)\(=\frac{2}{3}\left(\frac{2013}{2012}-\frac{1}{2012}\right)+\frac{1}{3}\)
\(=\frac{2}{3}\times1+\frac{1}{3}\)
\(=\frac{3}{3}=1\)
b)\(=\left(\frac{12}{199}+\frac{23}{200}-\frac{34}{201}\right).\left(\frac{3-2-1}{6}\right)\)
\(=\left(\frac{12}{199}+\frac{23}{200}-\frac{34}{201}\right).0\)
=0