Question

Đề bài

Tính:

a)    \({8^{{{\log }_2}5}}\)

b)    \({\left( {\frac{1}{{10}}} \right)^{\log 81}}\)

c)     \({5^{{{\log }_{25}}16}}\)

Answer 1

a: \(8^{log_25}=2^{3\cdot log_25}=5^3=125\)

b: \(\left(\dfrac{1}{10}\right)^{log81}=10^{-1\cdot log81}=81^{-1}=\dfrac{1}{81}\)

c: \(5^{log_{25}16}=5^{log_{5^2}16}=16^{-2}=\dfrac{1}{256}\)