25.关于xxx的不等式(a2−16)x2−(a−4)x−1⩾0(a^{2}-16)x^{2}-(a-4)x-1\geqslant 0(a2−16)x2−(a−4)x−1⩾0的解集为\O\O\O,则实数aaa的取值范围为 ___(−125(-\frac{12}{5}(−512[,]4)4)4)___.