\(\dfrac{x-2y}{x^2+xy}+\dfrac{x+2y}{x^2+xy}\)
\(=\dfrac{x-2y+x+2y}{x^2+xy}\)
\(=\dfrac{2x}{x\left(x+y\right)}=\dfrac{2}{x+y}\)
Ta có: \(\dfrac{{x - 2y}}{{{x^2} + xy}} + \dfrac{{x + 2y}}{{{x^2} + xy}} = \dfrac{{x - 2y + x + 2y}}{{{x^2} + xy}} = \dfrac{{2{\rm{x}}}}{{{x^2} + xy}}\)