Question

Suppose log 2 = r, log, 3= s, and log 5 = t. Which algebraic expression represents log 75?

Answer 1

log(75) = log( 3 • 5 • 5 )

= log(3) + log(5) + log (5)

= s + t + t

= s + 2t

To go from log( 3 • 5 • 5 ) to log(3) + log(5) + log (5), we use the log rule that says log( a • b ) = log(a) + log(b).