Question

Đề bài

Tính:

a)    \({\log _{12}}{12^3}\)

b)    \({\log _{0,5}}0,25\)

c)     \({\log _a}{a^{ - 3}}\,\,(a > 0;a \ne 1)\)

Answer 1

a) \(\log_{12}12^3=3.\log_{12}12=3.1=3\)

b) \(\log_{0,5}0,25=\log_{2^{-1}}2^{-2}=\dfrac{-2}{-1}\log_22=2.1=2\)

c) \(\log_aa^{-3}=-3.\log_aa=-3.1=-3\)

Answer 2

a: \(log_{12}12^3=3\)

b: \(=log_{0.5}0.5^2=2\)

c: \(log_aa^{-3}=-3\)