e);left(frac{x^2+1}{2x-1}-frac x2right)cdotfrac{1-2x}{x+2}=left(-frac{x^2+1}{1-2x}-frac x2right)cdotfrac{1-2x}{x+2}=-frac{x^2+1}{x+2}-frac{x-2x^2}{2(x+2)}=\=frac{-2x^2-2-x+2x^2}{2(x+2)}=frac{-x-2}{2(x+2)}=-frac{x+2}{2(x+2)}=-frac12\\3);frac3{5x}-frac3{x+y}cdotleft(frac{x+y}{5x}-x-yright)=frac3{5x}-frac3{x+y}cdotleft(frac{x+y}{5x}-(x+y)right)=\=frac3{5x}-frac3{5x}+3=3