How do you find the zero of this...thing: 0 = 100(1-e^-0.08t)-70

i need to solve for t and in order to do that apparently i need to find the 0 of
70 = 100(1-e^-0.08t)
(it said to subtract 70 to the other side so that's why you see the first equation with the 70 on the other side, then it said to solve for t by finding the 0)
idk how to do that.............PLEASE HELP!!! ;A;

70/100 = 1-e^-0.08t
e^-.08t =30/100
Ln [e^-0.08t]=Ln [0.3]
-.08t =ln [0.3]
t= -ln[0.3]/.08