Hoặc
Thực hiện phép nhân:
c) −23xy2+6yz2.−12xy .
c)−23xy2+6yz2.−12xy
=−23xy2.−12xy+6yz2.−12xy
=−23.−12.x.x.y2.y+6.−12.x.y.y.z2
=13x2y3−3xy2z2.