ĐKXĐ: $x\neq-3;x\neq0$
$\frac{x+1}{2x+6}$ + $\frac{2x+3}{x^2+3x}$
= $\frac{x+1}{2(x+3)}$ + $\frac{2x+3}{x(x+3)}$
= $\frac{x(x+1)}{2x(x+3)}$ + $\frac{2(2x+3)}{2x(x+3)}$
= $\frac{x^2+x+4x+6}{2x(x+3)}$
= $\frac{x^2+5x+6}{2x(x+3)}$
= $\frac{x^2+2x+3x+6}{2x(x+3)}$
= $\frac{x(x+2)+3(x+2)}{2x(x+3)}$
= $\frac{(x+2)(x+3)}{2x(x+3)}$
= $\frac{x+2}{2x}$