Before you go on to apply the Laws of Logarithms on a particular equation, confirm that it is of the type as given below:
ex = 80
Applying the appropriate law
The equation above suggests that you will have to apply one of the above three listed laws of logarithm. If you compare all three, it will be the third one which will solve the equation.
The Solution after applying law
Once you apply the law ln(x r ) = r ln(x) on ex = 80, you are actually taking log or ln on both sides of the equation.
Ln (ex ) = Ln (80)
X Ln (e) = Ln (80)
Since Ln (e) is equal to 1 so we write:
X = Ln (80)
As we look at the table of Logarithms for Ln (80), the value will be:
X = 4.38202663467
e4.38202663467 = 80