2. Представьте в виде дроби: a) $$rac{3x-1}{x^2} + \frac{x-9}{3x}$$; б) $$rac{5}{c+3} - \frac{5c-2}{c^2+3c}$$

a) $$rac{3x-1}{x^2} + \frac{x-9}{3x} = \frac{3(3x-1) + x(x-9)}{3x^2} = \frac{9x-3 + x^2 - 9x}{3x^2} = \frac{x^2 - 3}{3x^2}$$ б) $$rac{5}{c+3} - \frac{5c-2}{c^2+3c} = \frac{5}{c+3} - \frac{5c-2}{c(c+3)} = \frac{5c - (5c - 2)}{c(c+3)} = \frac{5c - 5c + 2}{c(c+3)} = \frac{2}{c(c+3)}$$