$\frac{3}{x-1} + \frac{2}{x+1} = $

$\frac{2}{x} + \frac{5y}{3x} = $

$\frac{-3}{x^{2}-4} + \frac{2}{x+2} = $

$\frac{2b}{b^{2}+5b+6} - \frac{5}{b+3} = $

$\frac{2x+7}{x-2} + \frac{2x-3}{2-x} = $

$\frac{8x+9}{4x} - \frac{5x-1}{2x} = $

$\frac{a}{16a^{2}-1} + \frac{1}{4a^{2}+1} = $