Given 2x=3y=6−z2^x = 3^y = 6^{-z}2x=3y=6−z, express zzz in terms of xxx and yyy.
z=−xyx+yz = -\frac{xy}{x+y}z=−x+yxy
z=xyx+yz = \frac{xy}{x+y}z=x+yxy
z=−x+yxyz = -\frac{x+y}{xy}z=−xyx+y
z=x+yxyz = \frac{x+y}{xy}z=xyx+y