Question

упростить выражение:

1) 3/5x^2y - 2/3xy^2 =

2) 6/5a-10 - 2/3a-6 =

3) -2/a+b + 3a+3b/a^2+2ab+b^2 =

Answer 1

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