a) Ta có: 128 = 38 . 216 và 912 = 324
=> 128 . 912 = 38 . 216. 324 = 216 . 332 = 216 . (32)16 = 216 . 916 = (2.9)16 = 1816
Vậy 128 . 912 = 1816
b) Ta có: 4510 = 510 . 320
=> 4510 . 530 = 320. 510 . 530 = 320 . 540 = 320 . (52)20 = 320 . 2520 = (3.25)20 = 7520
Vậy 4510 . 530 = 7520
a/ \(12^8.9^{12}=\left(2^2.3\right)^8.\left(3^2\right)^{12}=2^{16}.\left(3^2\right)^4.\left(3^2\right)^{12}=2^{16}.\left(3^2\right)^{16}=\left(2.9\right)^{16}=18^{16}\)
b/ \(75^{20}=\left(3.25\right)^{20}=\left(3^2\right)^{10}.\left(5^2\right)^{20}=9^{10}.5^{40}=9^{10}5^{10}.5^{30}=\left(9.5\right)^{10}.5^{30}=45^{10}.5^{30}\)
a. =(3.2^2)^8.9^12
=3^8.(2^2)^8.9^12
=2^16.(3^2)^4.9^12
=2^16.9^4.9^12
=2^16.9^16
=(2.9)^16=18^16
b.45^10.5^30=(3^2.5)^10.5^30
=(3^2)^10.5^10.5^30
=3^20.5^10.5^30
=3^20.5^40
=3^20.(5^2)^20
=3^20.25^20
=(3.25)^20
=75^20
k mk nha
a)Ta có:128.912=(22.3)8.912
=216.38.912
=216.(32)4.912
=216.94.912
=216.916
=1816
b)Ta có: 4510.530=(32.5)10.(52)15
=320.(52)5.2515
=320.255.2515
=320.2520
=7520
