－2（a－b）²＋3（a－b）³－½（b－a）²－3/2(a－b)³=-2(a-b)²+3(a-b)³-1/2(a-b)²-3/2(a-b)³=(-2-1/2)(a-b)²+(3-3/2)(a-b)³=-5/2(a-b)²+3/2(a-b)³...