How do you solve #log(x-15)+logx=2#?
Use the log property that
Since no base was specified we assume the base of the logarithm was
We know that
Expand the product and take that 100 to the LHS
Solve the quadratic in your favorite way, by the quadratic formula for example
However, recall that this was originally a logarithmic formula; we can have anything equal to 0 or a negative number in one!
So we know that