Evaluating base logarithms?
Hint: it is better if you change the base of logarithm, from 5 to 10. So, for example, the first logarithm is equal to: \[\Large {\log _5}80 = \frac{{{{\log }_{10}}80}}{{{{\log }_{10}}5}}\]
use the change of base formula on log_48 (3) to get log_48 (3) = log(48) / log(3) and then, I think you are expected to evaluate this with your calculator ie enter `( log ( 48 ) ) / ( log ( 3 ) ) =` this should match with the first part of some of the options
this should equal `some.number` so you have x = log_48 (3) = `some.number` Converting this to have a base of 5 x = log_5 ( 5 ^ `some.number` ) then evaluate 5 ^ `some.number` x = log_5 ( `another.number` )
and the right option will be of the form `some.number`; log_5 ( `another.number` )
@JoeJoldin Does it make any sense?
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