\[Дано:a < b\ \ и\ \ b > 0.\]
\[\frac{a}{5} < 0\]
\[\frac{- 4}{b} < 0\]
\[\frac{a}{b} < 0\]
\[\frac{a^{2}}{b} > 0\]
\[\left( \frac{b}{a} \right)^{5} < 0\]
\[\frac{a^{4}}{b^{7}} > 0\]