\(H=\dfrac{1}{7}\left(-0,28\right)+\dfrac{2}{14}\cdot16\%+\left(-3\dfrac{1}{7}\right)\cdot\dfrac{1}{25}\)
\(=\dfrac{1}{7}\cdot-\dfrac{7}{25}+\dfrac{1}{7}\cdot\dfrac{4}{25}-\dfrac{22}{7}\cdot\dfrac{1}{25}\\ =\dfrac{1}{7}\cdot-\dfrac{7}{25}+\dfrac{1}{7}\cdot\dfrac{4}{25}-\dfrac{1}{7}\cdot\dfrac{22}{25}\\ =\dfrac{1}{7}\left(-\dfrac{7}{25}+\dfrac{4}{25}-\dfrac{22}{25}\right)\\ =\dfrac{1}{7}\cdot\left(-1\right)\\ =-\dfrac{1}{7}\)