x/(x+3)+6/(x²-9)=1/(x-3)
x(x-3)/[(x+3)(x-3)]+6/[(x+3)(x-3)]=(x+3)/[(x+3)(x-3)]
(x²-3x+6-x-3)/[(x+3)(x-3)]=0
(x²-2x-3)/[(x+3)(x-3)]=0
[(x+1)(x-3)]/[(x+3)(x-3)]=0
(x+1)/(x+3)=0
x=1