$\frac{9 - 5b}{b} - \frac{7 - 5c}{c} = \frac{c(9 - 5b) - b(7 - 5c)}{bc} = \frac{9c - 5bc - 7b + 5bc}{bc} = \frac{9c - 7b}{bc}$

$\frac{4d + 7}{7d} - \frac{d - 6}{6d} = \frac{6(4d + 7) - 7(d - 6)}{42d} = \frac{24d + 42 - 7d + 42}{42d} = \frac{17d + 84}{42d}$

$\frac{5 - k}{5p} - \frac{p + 10}{5k} = \frac{k(5 - k) - p(p + 10)}{5kp} = \frac{5k - k^2 - p^2 - 10p}{5kp}$

$\frac{m - n}{mn} - \frac{p - n}{np} = \frac{p(m - n) - m(p - n)}{mnp} = \frac{mp - np - mp + mn}{mnp} = \frac{mn - np}{mnp} = \frac{n(m - p)}{mnp} = \frac{m - p}{mp}$

$\frac{6a + 2}{ab} - \frac{2a + 4}{a^2b} = \frac{a(6a + 2) - (2a + 4)}{a^2b} = \frac{6a^2 + 2a - 2a - 4}{a^2b} = \frac{6a^2 - 4}{a^2b}$

$\frac{c^2 - 16}{c^6} - \frac{c - 9}{c^5} = \frac{c^2 - 16 - c(c - 9)}{c^6} = \frac{c^2 - 16 - c^2 + 9c}{c^6} = \frac{9c - 16}{c^6}$

$\frac{1}{x^3} - \frac{1 + x^2}{x^5} = \frac{x^2 - (1 + x^2)}{x^5} = \frac{x^2 - 1 - x^2}{x^5} = \frac{-1}{x^5} = -\frac{1}{x^5}$

$\frac{1 - ab}{abc} - \frac{1 - ad}{acd} = \frac{d(1 - ab) - b(1 - ad)}{abcd} = \frac{d - abd - b + abd}{abcd} = \frac{d - b}{abcd}$