Really simple question

Hi

Sorry about this rather easy question but I'm not very good at maths and this is bugging me:

X^y = Z

If I know X and Z, how do I turn the equation around to determine the value of y?

Thanks in advance.

zing

If you were to take the logx (base x) of both sides this would yield:

y = logx(Z)

x^y = z

y log_ax = log_az

y = log_a(z - x)

Unless I've missed something.

Why not just take the log base x? That simplifies things a bunch...