\(12^8.9^{12}=4^8.3^8.9^{12}=2^{16}.9^4.9^{12}=2^{16}.9^{16}=\left(2.9\right)^{16}=18^{16}\left(đpcm\right)\)
\(12^8.9^{12}=(3.2^2)^8.(3^2)^{12}\)
\(=3^8.2^{16}.3^{24}=2^{16}.3^{8+24}=2^{16}.3^{32}\)
\(=2^{16}.9^{16}=(2.9)^{16}=18^{16}\)
Chứng minh :
12^8 . 9^12 = 18^16
Biến đổi VT ( vế trái ) : 12^8 . 9^12 = ( 2^2 . 3 )^8 . ( 3^2 )^12
= 2^16 .3^8 . 3^24 = 2^16 . 3^32
Biến đổi VP ( vế phải ) : 18^16 = ( 2 . 3^2 )^16 = 2^16 . 3^32
Vậy VT = VP
\(12^8.9^{12}=\left(3.2^2\right)^8.\left(3^2\right)^{12}\)
\(=3^8.2^{16}.3^{24}=2^{10}.3^{8+24}=2^{16}.3^{32}\)
\(=2^{16}.9^{16}=\left(2.9\right)^{16}\)
\(=18^{16}\left(đpcm\right)\)