x²-(2n+1)x+n²+n求解!

问题描述:

x²-(2n+1)x+n²+n求解!
不要用分解因式!用其他方法.

x²-(2n+1)x+n²+n
=(x-n-1/2)²-(n+1/2)²+n²+n
=(x-n-1/2)²-(1/2)²
=(x-n-1/2+1/2)(x-n-1/2-1/2)
=(x-n)(x-n-1)