G(Y)=(Y+1/a)(Y+1/b)(Y+1/c)(Y+1/d)=Y^4-CY^3+BY^2-AY-1
问题描述：
G(Y)=(Y+1/a)(Y+1/b)(Y+1/c)(Y+1/d)=Y^4-CY^3+BY^2-AY-1
答
学过排列组合吗?没学过的话就把它展开一一对应解答.比如Y^4前面系数肯定为1,常数项肯定是1/abcd=-1,所以abcd=-1,（1/a+1/b+1/c+1/d)=-C.自己想吧.