What is log 100 + log 10?

##3##
As we know
##log A+log B = log(A * B)##
This means that you can write
##log(100) + log(10) = log(100 * 10)##
##=log(1000)##
##=log(10^3)##
Since
##log(x^n) = n* log(x)##
you can say that
##log(10^3) = 3 * log(10) = 3 * 1 = 3##