已知a-b=2 ab=48 求﹣1/2a³b＋a²b²-1/2ab³

已知a-b=2 ab=48 求﹣1/2a³b＋a²b²-1/2ab³
已知a-b=2 ab=48 求﹣1/2a³b＋a²b²-1/2ab³

已知a-b=2 ab=48 求﹣1/2a³b＋a²b²-1/2ab³
﹣1/2a³b＋a²b²－1/2ab³
=－½ab﹙a²－2ab＋b²﹚
=－½ab﹙a－b﹚²
=－½×48×4
=－96

﹣1/2a³b＋a²b²-1/2ab³
=-1/2ab(a²-2ab+b²)
=-1/2ab(a-b)²
=-1/2*48*2²
=-96

﹣1/2a³b＋a²b²-1/2ab³
=-1/2ab(a²-2ab+b²)
=-1/2 * 48 (a-b)²
=-24* 4
=-96

﹣1/2a³b＋a²b²-1/2ab³
=-1/2ab(a-b)²
=-1/2×48×4
=-96

5/2,1/4 a+b=√3得(a+b)^2=a^2 +2ab + b^2=3，据加法交换律和结合律有(a^2+ b^2)+2ab =3，这是1式。 (a-b)^2=2得a^2

已知a-b=2 ab=48 求﹣1/2a³b＋a²b²-1/2ab³
这题目太简单了吧
1/2a³b＋a²b²-1/2ab³
= a3b+2a2b2-ab3
=ab(a2+2ab-b2)
=ab(a-b)2
=48*22
=192