\(\dfrac{28^7.5^8.15^9}{14^8.25^9.6^{12}}=\dfrac{2^7.14^7.5^8.5^9.3^9}{14^7.14.\left(5^2\right)^9.3^{12}.2^{12}}\\ =\dfrac{14^7.5^{17}.3^9.2^7}{14^7.14.5^{17}.5.3^9.3^3.2^7.2^5}\\ =\dfrac{1}{14.5.3^3.2^5}=\dfrac{1}{14.5.27.32}\\ =\dfrac{1}{60480}\)
\(\dfrac{28^7.5^8.15^9}{14^8.25^9.6^{12}}\\ =\dfrac{2^7.14^7.5^8.5^9.3^9}{14^8.5^9.5^9.3^{12}.2^{12}}\\ =\dfrac{1}{14.5.3^3.2^5}\\ =\dfrac{1}{60480}\)
\(\dfrac{28^7\cdot5^8\cdot15^9}{14^8\cdot25^9\cdot6^{12}}\)
=\(\dfrac{14^7\cdot2^7\cdot5^8\cdot3^9\cdot5^9}{14^8\cdot5^{18}\cdot2^{12}\cdot3^{12}}\)
=\(\dfrac{14^7\cdot2^7\cdot5^{17}\cdot3^9}{14^8\cdot2^{12}\cdot5^{18}\cdot3^{12}}\)
=\(\dfrac{1}{14\cdot2^5\cdot5\cdot3^3}\)=\(\dfrac{1}{60480}\).
