>>263
(1)
3(x^2)+8x-3=(3x-1)(x+3)
(x^3)+1 = (x+1)((x^2)-x+1)
9(x^3)-x = x(9(x^2)-1)=x(3x-1)(3x+1)

{(3(x^2)+8x-3)/((x^2)-x+1)}÷{(9(x^3)-x)/((x^3)+1)} {x/(x+3)}
= {(3x-1)(x+3)/((x^2)-x+1)} { (x+1)((x^2)-x+1)/(x(3x-1)(3x+1))} {x/(x+3)}
= (x+1)/(3x+1)