1 / (6х+10) - 1 / (9х-15) + 5 / (9х²-25) = 1 / 6*(3х-5),
1 / 2*(3х+5) - 1 / 3*(3х-5) + 5 / (3х-5)(3х+5) = 1 / 6*(3х-5),
3*(3х-5) / 6*(3х-5)(3х+5) - 2*(3х+5) / 6*(3х-5)(3х+5) + 5*6 / 6*(3х-5)(3х+5) =
= 1 / 6*(3х-5),
(9х-15 - 6х-10 + 30) / 6*(3х-5)(3х+5) = 1 / 6*(3х-5),
(3х+5) / 6*(3х-5)(3х+5) = 1 / 6*(3х-5),
1 / 6*(3х-5) = 1 / 6*(3х-5)
тождество выражений доказано