## Algebra: A Combined Approach (4th Edition)

The answer is both option (a) $\frac{\log 7}{\log 2}$ and (b) $\frac{\ln 7}{\ln 2}$
According to the 'Change of base law', $\log_{2} 7$ can be written correctly as both $\frac{\log 7}{\log 2}$ or $\frac{\ln 7}{\ln 2}$.