a) \(8^4.16^5\)
\(=\left(2^3\right)^4.\left(2^4\right)^5\\ =2^{3.4}.2^{4.5}\\ =2^{12}.2^{20}\\ =2^{12+20}\\ =2^{32}\)
b) \(5^{40}.125^2.625^3\)
\(=5^{40}.\left(5^3\right)^2.\left(5^4\right)^3\)
\(=5^{40}.5^{3.2}.5^{4.3}\)
\(=5^{40}.5^6.5^{12}\)
\(=5^{40+6+12}\)
\(=5^{58}\)
c) \(27^4.81^{10}\)
\(=\left(3^3\right)^4.\left(3^4\right)^{10}\)
\(=3^{3.4}.3^{4.10}\)
\(=3^{12}.3^{40}\)
\(=3^{52}\)
d) \(10^3.100^5.1000^4\)
\(=10^3.\left(10^2\right)^5.\left(10^3\right)^4\)
\(=10^3.10^{2.5}.10^{3.4}\)
\(=10^3.10^{10}.10^{12}\)
\(=10^{3+10+12}\)
\(=10^{25}\)