b) 2xy- 3y^2/ x^2 - 3xy -x/ 3x - 9y .
Giải thích
b) 2xy−3y2x2−3xy−x3x−9y=y(2x−3y)x(x−3y)−x3(x−3y)
=3y(2x−3y)3x(x−3y)−x23x(x−3y)=3y(2x−3y)−x23x(x−3y)
=6xy−9y2−x23x(x−3y)=−x2−6xy+(3y)23x(x−3y)
=−(x−3y)23x(x−3y)=−x−3y3x=3y−x3x.
b) 2xy−3y2x2−3xy−x3x−9y=y(2x−3y)x(x−3y)−x3(x−3y)
=3y(2x−3y)3x(x−3y)−x23x(x−3y)=3y(2x−3y)−x23x(x−3y)
=6xy−9y2−x23x(x−3y)=−x2−6xy+(3y)23x(x−3y)
=−(x−3y)23x(x−3y)=−x−3y3x=3y−x3x.