22．函数y=11−2x+log5(2x+1)y=\frac{1}{\sqrt{1-{2^x}}}+{\log _5}({2x+1})y=1−2x1+log5(2x+1)的定义域为 ___(−12,0)({-\frac{1}{2},0})(−21,0)___．