Представьте в виде дроби: a) $$\frac{3-2a}{2a} - \frac{1-a^2}{a^2}$$; б) $$\frac{1}{3x+y} + \frac{1}{3x-y}$$; в) $$\frac{3}{b-2} - \frac{4-3b}{b^2-2b}$$

a) $$\frac{3-2a}{2a} - \frac{1-a^2}{a^2} = \frac{a(3-2a)-2(1-a^2)}{2a^2} = \frac{3a-2a^2-2+2a^2}{2a^2} = \frac{3a-2}{2a^2}$$. б) $$\frac{1}{3x+y} + \frac{1}{3x-y} = \frac{3x-y+3x+y}{(3x+y)(3x-y)} = \frac{6x}{9x^2-y^2}$$. в) $$\frac{3}{b-2} - \frac{4-3b}{b^2-2b} = \frac{3}{b-2} - \frac{4-3b}{b(b-2)} = \frac{3b-(4-3b)}{b(b-2)} = \frac{3b-4+3b}{b(b-2)} = \frac{6b-4}{b(b-2)} = \frac{2(3b-2)}{b(b-2)}$$