a的三次方-3a的平方+3a-1
来源:学生作业学帮网 编辑:学帮网 时间:2024/07/05 08:28:46
a的三次方-3a的平方+3a-1
a ³ -3a²+3a-1
=(a ³ -1)-(3a²-3a)
=(a-1)(a ²+a+1)-3a(a-1)
=(a-1)(a ²+a+1-3a)
=(a-1)(a -1)²
=(a-1) ³
原式=(a^3-1)-(3a^2-3a)
=(a-1)(a^2+a+1)-3a(a-1)
=(a-1)(a^2-2a+1)
=(a-1)^3
是3*a方还是[3a]方啊