化简-x2-3x+2x2+4x.xy2-2/3x2y-xy2/2+2x2y.2a-1/2ab-(a2-ab)

问题描述:

化简-x2-3x+2x2+4x.xy2-2/3x2y-xy2/2+2x2y.2a
-1/2ab-(a2-ab)

1) --x^2--3x+2x^2+4x
=x^2+x.
2) xy^2--(2/3)x^2y--xy^2/2+2x^2y
=(1/2)xy^2+(4/3)x^2y.
3) 2a--(1/2)ab--(a^2--ab)
=2a--(1/2)ab--a^2+ab
=2a+(1/2)ab--a^2.