TeX源碼:

EV=(1-a)(\frac{a}{p})^{\frac{a}{1-a}}-(1-a)(\frac{a}{p+t})^{\frac{a}{1-a}}=(1-a)(\frac{a}{p})^{\frac{a}{1-a}}(1-(\frac{p}{p+t})^{\frac{a}{1-a}})