问题
填空题
计算:5x(x2-2x+4)+x2(x-1)
答案
解: 5x(x2-2x+4)+x2(x-1)
=(5×1)·x·x2-(5×2)·x·x+(5×4)·x+x2·x-(1×1)x2
=5x3-10x2+20x+x3-x2
=6x3-11x2+20x
计算:5x(x2-2x+4)+x2(x-1)
解: 5x(x2-2x+4)+x2(x-1)
=(5×1)·x·x2-(5×2)·x·x+(5×4)·x+x2·x-(1×1)x2
=5x3-10x2+20x+x3-x2
=6x3-11x2+20x