Ta có: \(\frac{5}{{2{{\rm{x}}^2}\left( {6{\rm{x}} + y} \right)}} + \frac{3}{{5{\rm{x}}y\left( {6{\rm{x}} + y} \right)}} = \frac{{25y}}{{10{{\rm{x}}^2}y\left( {6{\rm{x}} + y} \right)}} + \frac{{6{\rm{x}}}}{{10{{\rm{x}}^2}y\left( {6{\rm{x}} + y} \right)}} = \frac{{25y + 6{\rm{x}}}}{{10{{\rm{x}}^2}y\left( {6{\rm{x}} + y} \right)}}\)