SOLVE FOR B from given equation

This is a logistic function. and how would i solve for B in this equation? steps please?

90= 150/(1+180e^(-b*t)) <-- (b times t)

thanks!!!!

1 + 180e^(-bt) = 150/90 = 5/3
180e^(-bt) = 2/3
e^(-bt) = 1/270
-bt = -ln 270
bt = ln 270

Unless we know the value of t, we cannot solve for b.

90= 150/(1+180e^(-b*t))

1+180e^(-b*t) = 5/3

180e^(-b*t) = 2/3

e^(-b*t) = 1/270

-bt = ln(1/270)

bt = ln(270)

b = (1/t)ln(270)