Thu gọn biểu thức: d) ( x + 3 y ) ( x − 2 y ) − ( x^ 4 y − 6 x^ 2 y ^3 ) : x ^2 y .

d)\(\left( {x + 3y} \right)\left( {x - 2y} \right) - \left( {{x^4}y - 6{x^2}{y^3}} \right):{x^2}y\)

\( = {x^2} - 2xy + 3xy - 6{y^2} - \left( {{x^2} - 6{y^2}} \right)\)

\( = {x^2} + xy - 6{y^2} - {x^2} + 6{y^2}\)

\( = xy\).