2^10S30-(2^10+1)S30+S10=0 ==> S30 = S10 ==> a11+...+a30 = 0 ==> a11(1+q+...+q^19) = 0 显然q 不等于0或1,所以:1+q+...+q^19 = 0 ==> q^20 = 1 (两边同时乘以 q - 1)==> q的值,你自己去验证下看看
2^10S30-(2^10+1)S30+S10=0 ==> S30 = S10 ==> a11+...+a30 = 0 ==> a11(1+q+...+q^19) = 0 显然q 不等于0或1,所以:1+q+...+q^19 = 0 ==> q^20 = 1 (两边同时乘以 q - 1)==> q的值,你自己去验证下看看