Đáp án:
 
Giải thích các bước giải:
 Bài 1:
a) `12^8 . 9 ^12 = 18^16`
`VT=12^8 . 9 ^12=(4.3)^8 . 9^{12}`
`VT=4^8 .3^8. 9^{12}=(2^{2})^8. (3^{2})^{4}.9^{12}`
`VT=2^{16}.9^{4}.9^{12}=2^{16}.9^{16}=18^{16}=VP`
b) `45^{10}.5^{30}=75^{20}`
`VT=45^{10}.5^{30}=(9.5)^{10}.5^{30}`
`VT=9^{10}.5^{10}.5^{30}=(3^{2})^{10}.5^{40}`
`VT=3^{20}.(5^{2})^{20}=3^{20}.25^{20}`
`VT=(3.25)^{20}=75^{20}=VP`