Ответ:\(2.5^{-2/3}=\dfrac{1}{\sqrt[3]{(2.5)^2}}\).\(\left(\dfrac{1}{9}\right)^{-1/2}=\dfrac{1}{\sqrt{1/9}}=3\).\(0.5^{0.5}=0.5^{1/2}=\sqrt{0.5}\).