计算:4﹙a-b﹚²-﹙2a+b﹚﹙﹣b+2a﹚
问题描述:
计算:4﹙a-b﹚²-﹙2a+b﹚﹙﹣b+2a﹚
答
4﹙a-b﹚²-﹙2a+b﹚﹙﹣b+2a﹚
=4﹙a-b﹚²-﹙2a+b﹚﹙2a-b)=4(a^2+b^2-2ab)-4a^2+b^2=5b^2-8ab
答
化简是吗?
5b^2-8ab
答
4﹙a-b﹚²-﹙2a+b﹚﹙﹣b+2a﹚
=4﹙a²-2ab+b²﹚ +﹙2a+b﹚﹙b-2a﹚
=4a²-8ab+4b² +b² - 4a²
=5b² - 8ab
答
4﹙a-b﹚²-﹙2a+b﹚﹙﹣b+2a﹚=4﹙a-b﹚²-﹙2a+b﹚﹙2a-b﹚=4﹙a-b﹚²-﹙4a²-b²﹚=4a²-8ab+4b²-4a²+b²=-8ab+5b²