SOLUTION: 100e^-0.13t=50 100=20(1.2)^x+2

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Question 960242: 100e^-0.13t=50
100=20(1.2)^x+2
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
a.) 100e^-0.13t=50
e^(-0.13t)=50/100=1/2
take log of both sides
-0.13t*lne=ln(1/2)
lne=1
-0.13t=ln(1/2)
t= ln(1/2)/-0.13
t=-5.3319
..
b.) 100=20(1.2)^x+2
98=20(1.2)^x
1.2^x=98/20=4.9
xlog1.2=log4.9
x=log 4.9/log1.2
x=8.7167