Logarithm problem, thanks?

y=C*x^n
log(y)=log(C*x^n)
=log(C)+log(x^n)
=log(C)+n*log(x)
when log(y)=0 , log(x)=-3
so 0=log(C)+n*(-3)
but I don't know the log(y)-intercept
so I can't find the answer until you give me the log(y)-intercept or Slope

欠log y-intercept