解 [n²/2+11n²/2]-[(n-1)²/2+11(n-1)/2] 要过程

问题描述:

解 [n²/2+11n²/2]-[(n-1)²/2+11(n-1)/2] 要过程

[n²/2+11n²/2]-[(n-1)²/2+11(n-1)/2] =n^2/2 + 11n^2/2 - ((n-1)^2/2 + 11(n-1)/2)=n^2/2 + 11n^2/2 - ((n-1)^2 + 11(n-1)/2)=n^2/2 + 11n^2/2 - ((n-1)(n-1)^(2-1) + 11/2)=n^2/2 + 11n^2/2 - ((n-1...