\(\dfrac{5^{100}.9^{1000}}{3^{2000}.25^{50}}\)
\(=\dfrac{5^{100}.\left(3^2\right)^{1000}}{3^{2000}.\left(5^2\right)^{50}}\)
\(=\dfrac{5^{100}.3^{2000}}{3^{2000}.5^{100}}\)
\(=1\)
\(\dfrac{5^{100}.9^{1000}}{3^{2000}.25^{50}}=\dfrac{5^{100}.\left(3^2\right)^{1000}}{3^{2000}.\left(5^2\right)^{50}}=\dfrac{5^{100}.3^{2000}}{3^{2000}.5^{100}}=1\)