高中数学题,求过程详细解答,谢谢了!!!!

2025-04-29 20:58:00
推荐回答(1个)
回答1:

(1-1/x) (1+x)^5

(1)
coef. of x^2
=(5C2) - (5C3)
=0
(2)
5Cr - 5C(r+1)= 0
r= 2
coef. of x^2 =0