第10章 10.3

(1)

$\log_5 x = 3 \qquad 5^3 = x \qquad x = 125$

(2)

$\log_{10} x = -2 \qquad 10^{-2} = x \qquad x = \dfrac{1}{100}$

(3)

$\log_4 x = 0 \qquad 4^0 = x \qquad x = 1$

(4)

$\log_{16} x = \dfrac{1}{4} \qquad 16^{\frac{1}{4}} = x \qquad x = 2$

(5)

$\log_{25} x = -\dfrac{1}{2} \qquad 25^{-\frac{1}{2}} = x \qquad x = \dfrac{1}{5}$

(6)

$\log_8 x = -\dfrac{4}{3} \qquad 8^{-\frac{4}{3}} = x \qquad x = 2^{-4} = \dfrac{1}{16}$