Step-by-step explanation:
Since the question has already been answered, I'd like to add something new, and explain why: 
So let's just say that:
 and that
 and that 
This means that:  and that
 and that  .
. 
So if we were to multiply the two, a and c. You get
 
 
This is due to the exponent identity that: 
So if you rewrite this in logarithmic form you get:

and remember what x and y are equal to? that's right, it's the logarithms
so now you substitute the logarithms back in and get
