求代数式a³-(-a²+2a-1)= 的值a³-(-a²+2a-1)= ﹙_________﹚+(a²+1)

问题描述:

求代数式a³-(-a²+2a-1)= 的值
a³-(-a²+2a-1)= ﹙_________﹚+(a²+1)

a(a²-2)

a³-(-a²+2a-1)=﹙a³-2a﹚+(a²+1)

-2a+1

a³-2a

a³-(-a²+2a-1)
= a³+a²-2a+1 (除括号)
=a³-2a+a²+1 (移项,符号连同一起移)
=(a³-2a)+(a²+1)