6-2x分之x-1=(x-1)/(6-2x)=(1-x)/2(x-3)=(1-x)(x+3)²/(2(x-3)(x+3)²
x²-9分之6=6/(x-3)(x+3)=12(x+3)/2(x-3)(x+3)²
x²+6x+9分之x=x/(x+3)²=2x(x-3)/2(x-3)(x+3)²