n^3+3n^2+2n=n(n+1)(n+2)
(1)n=1时取最小值6
(2) 1X2X3 2X3X4 3X4X5 .
显然其最大公约数为6n^3+3n^2+2n=n(n+1)(n+2)求过程怎么来的？我知道n^3+3n^2+2n=n（n^2+3n+2）=n[(n^2+2n+1)+(n+1)]=n[(n+1)^2+(n+1)]到这他是怎么变成=n(n+1)(n+2)的！(n+1)^2+(n+1)=(n+1)[(n+1)+1)]=(n+1)(n+2)再将（n+1)提出来