3x 3x плиз,очень нужно**
--- + ---
x+3 x-3
3х(х-3)+3х(х+3) 3х(х-3+х+3) 6х^2
______________= ___________=_______
(х+3)(х-3) (х+3)(х-3) х^2+9
3x 3x 3x²-9x+3x²+9x 6x²
___+___= ______________ = ____
x+3 x-3 (x-3)(x+3) x²-9