б) $$\frac{12p-1}{3p^2} - \frac{1-3p}{3p^2} = \frac{12p - 1 - (1 - 3p)}{3p^2} = \frac{12p - 1 - 1 + 3p}{3p^2} = \frac{15p - 2}{3p^2}$$
в) $$\frac{6y-3}{5y} - \frac{y+2}{5y} = \frac{6y - 3 - (y + 2)}{5y} = \frac{6y - 3 - y - 2}{5y} = \frac{5y - 5}{5y} = \frac{5(y-1)}{5y} = \frac{y-1}{y}$$
г) $$\frac{3p-q}{5p} - \frac{2p+6q}{5p} + \frac{p-4q}{5p} = \frac{3p - q - (2p + 6q) + (p - 4q)}{5p} = \frac{3p - q - 2p - 6q + p - 4q}{5p} = \frac{2p - 11q}{5p}$$
д) $$\frac{5c-2d}{4c} - \frac{3d}{4c} + \frac{d-5c}{4c} = \frac{5c - 2d - 3d + (d - 5c)}{4c} = \frac{5c - 2d - 3d + d - 5c}{4c} = \frac{-4d}{4c} = -\frac{d}{c}$$
e) $$\frac{2a}{b} - \frac{1-6a}{b} + \frac{13-8a}{b} = \frac{2a - (1-6a) + (13 - 8a)}{b} = \frac{2a - 1 + 6a + 13 - 8a}{b} = \frac{12}{b}$$