Представьте в виде дроби 7/(a+5)-(7a-3)/(a^2+5a)

\[\ \frac{7}{a + 5} - \frac{7a - 3}{a^{2} + 5a} = \frac{7^{\backslash a}}{a + 5} - \frac{7a - 3}{a(a + 5)} =\]

\[= \frac{7a - 7a + 3}{a(a + 5)} = \frac{3}{a^{2} + 5}\]

\[\frac{14b^{2} - c}{7b} - 2b^{\backslash 7b} = \frac{14b^{2} - c - 14b^{2}}{7b} = \frac{- c}{7b}\]

\[при\ b = 0,5\ \ и\ \ c = - 14:\]

\[\frac{- c}{7b} = \frac{14}{7 \cdot 0,5} = \frac{14}{3,5} = 4.\]