a) 12^{8}.9^{12}=(2^{2}.3)^{8}.9^{12} =(2^{2})^{8}.3^{8}.9^{12} =2^{16}.9^{4}.9^{12} =2^{16}.9^{16} =(2.9)^{16} = 18^{16}vậy 12^{8}.9^{12}=18^{16}
a)
$12^{8}.9^{12}=(2^{2}.3)^{8}.9^{12}
$ $=(2^{2})^{8}.3^{8}.9^{12}
$ $=2^{16}.9^{4}.9^{12}
$ $=2^{16}.9^{16}
$ $=(2.9)^{16}
$ $= 18^{16}
$vậy
$12^{8}.9^{12}=18^{16}
$