SOLUTION: I need help solving this! How long will it take a sample radioactive substance to decay to half of its original amount, if it decays according to the function A(t)=450e^-0.157t, wh

Algebra ->  Expressions -> SOLUTION: I need help solving this! How long will it take a sample radioactive substance to decay to half of its original amount, if it decays according to the function A(t)=450e^-0.157t, wh      Log On


   

Question 276156: I need help solving this! How long will it take a sample radioactive substance to decay to half of its original amount, if it decays according to the function A(t)=450e^-0.157t, where t is the time years? Round to the nearest hundreth year.
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
1/2 = 450 e^(-0.157t)

.5 / 450 = e^(-0.157t)

ln(.5 / 450) = -0.157 t

[ln(.5 / 450)] / (-0.157) = t