Question

(x+3)/(x^2+3)*((x+3)/(x-3)-(x-3)/(x+3))

Answer 1

   $\frac{x+3}{x^2+3}*(\frac{x+3}{x-3}-\frac{x-3}{x+3} )=$

$=\frac{x+3}{x^2+3}*\frac{(x+3)*(x+3)-(x-3)*(x-3)}{(x-3)*(x+3)}=$

$=\frac{x+3}{x^2+3}*\frac{x^2+6x+9-x^2+6x-9}{(x-3)(x+3)}=$

$=\frac{(x+3)*12x}{(x^2+3)(x-3)(x+3)}=$

$=\frac{12x}{(x^2+3)(x-3)}$

Answer 2

(x+3)/(x²+3)*((x+3)/(x-3)-(x-3)/(x+3))=

((х+3)*(х²+9+6х-х²+6х-9)/((х²+3)*(х+3)(х-3))=

12х/((х-3)(х²+3))