Question

ln(y+1)+ln8=x+lnx

Answer 1

Not sure what you want to do with that. We can express y as a function x:

ln(y+1)+ln8 = x + lnx
ln (y+1)*8 = x + lnx
(y+1)*8 = e^(x + lnx)
8(y+1) = e^lnx * e^x
8(y+1) = x e^x
y+1 = 1/8 x e^x
y = 1/8 x e^x - 1