Tính: (12x^3y + 3xy - 4x^2y^2) : 4xy

* Hướng dẫn giải

$\begin{array}{l}\left(12{\mathrm{x}}^3\mathrm{y}+3\mathrm{xy}-4{\mathrm{x}}^2{\mathrm{y}}^2\right):4\mathrm{xy}\\ =\left(12{\mathrm{x}}^3\mathrm{y}:4\mathrm{xy}\right)+\left(3\mathrm{xy}:4\mathrm{xy}\right)-\left(4{\mathrm{x}}^2{\mathrm{y}}^2:4\mathrm{xy}\right)\\ =3{\mathrm{x}}^2+\frac{3}{4}-\mathrm{xy}\end{array}$