3х 5 х²-4 3х - 5*(х+2) х²-4
( -------------- - ------------- ) * ----------- = ( ------------------ ) * ----------- =
(х-2)(х+2) (х-2) х+5 (х²-4) х+5
3х-5х-10 х²-4 (-2х-10) * (х²-4) -2(х+5) * (х²-4)
------------ * -------- = ------------------------ = ----------------------- = -2
х²-4 х+5 (х²-4) *(х+5) (х²-4) *(х+5)