SOLUTION: 123=500e^-0.12x

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Question 569464: 123=500e^-0.12x
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Assume the problem is:
123=500e%5E%28-0.12x%29
rewrite it
500e%5E%28-0.12x%29 = 123
divide both sides by 500
e%5E%28-0.12x%29 = 123%2F500
e%5E%28-0.12x%29 = .246
:
Using nat logs
ln%28e%5E%28-0.12x%29%29 = ln(.246)
:
the log equiv of exponents
-.12x*ln(e) = ln(.246)
;
find e%5Ex of both sides, the nat log of e is 1
-.12x = -1.4024
;
x = %28-1.4024%29%2F%28-.12%29
x = +11.6869
:
:
We can check this on a good calc: enter 500*e^(-.12*11.6869). results 122.999 ~ 123