e^-.02x=4?

I assume this is....

e^(-.02x)=4      take the ln of both sides

lne^(-.02x)=ln(4)     and by a property of logs, we have

(-.02x)ln(e) = ln(4)     and ln(e) = 1  .....so we  have

-.02x = ln(4)         divide both sides by -.02

x = ln(4)/(-.02) = about -69.3