可以用双十字吗?
不行的话,用其他方法
可以用双十字吗?
不行的话,用其他方法
a^4+6a^3+11a^2+6a+1
=a^4+2a^3+4a^3+8a^2+3a^2+6a+1
=a^3{a+2]+4a^2{a+2]+3a{a+2}+1
={a^3+4a^2+3a]{a+2}+1
=a{a^2+4a+3][a+2}+1
=a{a+1]{a+3}[a+2}+1
=[a{a+3}} *{a+1][a+2}+1
=[a^2+3a][a^2+3a+2]+1
=[a^2+3a]^2+2[a^2+3a]+1
=(a^2+3a+1)^2