a)414.528
=414.(52)14
=414.2514
=(4.25)14=10014
b)12n:22n
=12n:(22)n
=12n:4n
=(12:4)n=3n
a, \(4^{14}.5^{28}\)
\(4^{14}.5^{28}=4^{14}.\left(5^2\right)^{14}\)
\(=4^{14}.25^{14}=\left(4.25\right)^{14}=100^{14}\)
b, \(12^n:2^{2n}\)
\(12^n:2^{2n}=12^n:\left(2^2\right)^n\)
\(12^n:\left(2^2\right)^n=12^n:4^n=\left(12:4\right)^n=3^n\)