Good Morning!
See Below ***
Note:
2^d = 645
base conversion formula
d == 2.8/.30 = 9.333...
Per Your Question***: These are (base 10)
Found by Your calculator by simply using log function(calculator automatically uses base 10)
and entering either 645 0r 2
Checking:
2^9.33333 = 645 (rounded) Checks!
------- Converting to LOGARITHMIC form
------ Applying change of base
Calculate this to get: d = 9.33315535