24.函数f(x)=log12(2x2−3x−2)f(x)={\log _{\frac{1}{2}}}({2{x^2}-3x-2})f(x)=log21(2x2−3x−2)的单调递增区间为 ___(−∞,−12)(-\infty ,-\frac{1}{2})(−∞,−21)___.