a) \(3-\left(-\dfrac{6}{7}\right)^0+\left(\dfrac{1}{2}\right)^2:2\)
\(=3-1+\dfrac{1}{4}\cdot\dfrac{1}{2}\)
\(=2+\dfrac{1}{8}\)
\(=\dfrac{16}{8}+\dfrac{1}{8}=\dfrac{17}{8}\)
\(a.3-\left(\dfrac{-6}{7}\right)^0+\left(\dfrac{1}{2}\right)^2:2\)
\(=3-1+\dfrac{1}{4}:2\)
\(=2+\dfrac{1}{8}\)
=\(\dfrac{16}{8}+\dfrac{1}{8}\)
\(=\dfrac{17}{8}\)