<Dl> <Dd> log b ⁡ (b x) = x log b ⁡ b = x . (\ displaystyle \ log _ (b) \ left (b ^ (x) \ right) = x \ log _ (b) b = x .) </Dd> </Dl> <Dd> log b ⁡ (b x) = x log b ⁡ b = x . (\ displaystyle \ log _ (b) \ left (b ^ (x) \ right) = x \ log _ (b) b = x .) </Dd> <P> In prose, taking the x-th power of b and then the base - b logarithm gives back x . Conversely, given a positive number y, the formula </P> <Dl> <Dd> b log b ⁡ y = y (\ displaystyle b ^ (\ log _ (b) y) = y) </Dd> </Dl>

What is the approximate value of x where log10(x) = 9.1