2. Представьте в виде дроби.

Решения: а) \(\frac{y - 20}{4y} + \frac{5y - 2}{y^2}\): \[\frac{y - 20}{4y} + \frac{5y - 2}{y^2} = \frac{(y - 20)y + 4(5y - 2)}{4y^2} = \frac{y^2 - 20y + 20y - 8}{4y^2} = \frac{y^2 - 8}{4y^2}.\] б) \(\frac{1}{5c - d} - \frac{1}{5c + d}\): \[\frac{1}{5c - d} - \frac{1}{5c + d} = \frac{(5c + d) - (5c - d)}{(5c - d)(5c + d)} = \frac{2d}{25c^2 - d^2}.\] в) \(\frac{7}{a + 5} - \frac{7a - 3}{a^2 + 5a}\): \[\frac{7}{a + 5} - \frac{7a - 3}{a^2 + 5a} = \frac{7}{a + 5} - \frac{7a - 3}{a(a + 5)} = \frac{7a - (7a - 3)}{a(a + 5)} = \frac{3}{a(a + 5)}.\]