I'm not sure what the "^4" means but I will guess that it is the base of the logarithm. I am used to that being written as asubscript,after. If that is correct then the equation is .

Now, " " is the same as " ". Do you notice that all of those bases are powers of 2? , and . So is the same as and so , thus . , so , thus and . Similarly, so the equation can be written

If we let that is the same as .

Can you solve that?