I need to rearrange this:
log x + log y = z
to prove that
z = log xy
I've managed to get to:
x = 10(raised to) z - log y
Don't know if I'm going in the right direction, or where to go from there
From Wikipedia$\displaystyle \log_b(xy) = \log_b(x) + \log_b(y) \!\,$ because $\displaystyle b^x \cdot b^y = b^{x + y} \!\, $
In detail:
$\displaystyle b^{\log_bx}=x,\enspace b^{\log_by}=y\rightarrow b^{\log_bx+\log_by}=xy=b^{\log_b(xy)}$