Ta có
$P = \dfrac{2}{2x+3} + \dfrac{3}{2x+1} - \dfrac{6x+5}{(2x-3)(2x+3)}$
$= \dfrac{2(2x+1)(2x-3) + 3(2x+3)(2x-3) - (6x+5)(2x+1)}{(2x-3)(2x+3)(2x+1)}$
$= \dfrac{8x^2 -8x -6 + 12x^2 -27 - (12x^2 +16x + 5)}{(2x-3)(2x+3)(2x+1)}$
$= \dfrac{8x^2 -24x -38}{(2x-3)(2x+3)(2x+1)}$