a) \(2^5\cdot8^4\\ =2^5\cdot\left(2^3\right)^4\\ =2^5\cdot2^{12}\\ =2^{17}\)
b) \(25^6\cdot125^3\\ =\left(5^2\right)^6\cdot\left(5^3\right)^3\\ =5^{12}\cdot5^9\\ =5^{21}\)
c) \(625^3:25^7\\ =\left(5^4\right)^3:\left(5^2\right)^7\\ =5^{12}:5^{14}\\ =5^{-2}=\frac{1}{5^2}\)
d) \(4^{10}\cdot2^{30}\\ =\left(2^2\right)^{10}\cdot2^{30}\\ =2^{20}\cdot2^{30}\\= 2^{50}\)
e) \(9^{25}\cdot27^4\cdot81^3\\ =\left(3^2\right)^{25}\cdot\left(3^3\right)^4\cdot\left(3^4\right)^3\\ =3^{50}\cdot3^{12}\cdot3^{12}\\ =3^{74}\)