\[\frac{a^{2} - b}{a} - a^{\backslash a} = \frac{a^{2} - b - a^{2}}{a} = \frac{- b}{a}\]
\[при\ a = 0,2\ и\ b = - 5:\]
\[\text{\ \ \ }\frac{- b}{a} = \frac{5}{0,2} = 5 \cdot \frac{10}{2} = 25.\]