Упростить выражение: 1) 3/5x^2y - 2/3xy^2 = 2) 6/5a-10 - 2/3a-6 = 3) -2/a+b +...

Решите задачу:

$\frac{3}{5x^2y} - \frac{2}{3xy^2} = \frac{3*3y -2*5x}{5*3x^2y^2} = \frac{9y-10x}{15x^2y^2} \\ \\ \\ \frac{6}{5a-10} - \frac{2}{3a-6} = \frac{6}{5*(a-2)} - \frac{2}{3*(a-2)} = \frac{6*3-2*5}{5*3*(a-2)} = \frac{18-10}{15(a-2)} = \\ \\ = \frac{8}{15(a-2)} = \frac{8}{15a-30} \\ \\ \\ - \frac{2}{a+b} + \frac{3a+3b}{a^2+2ab+b^2} = - \frac{2}{a+b} + \frac{3(a+b)}{(a+b)^2} = - \frac{2}{a+b} + \frac{3}{a+b} = \frac{-2+3}{a+b} = \\ \\ = \frac{1}{a+b}$