SOLUTION: How large do you need to make x so that e^(-x/9) that is less than 0.1? I tried inputting values for x and I came up with 21 as the value for x.

Question 68062: How large do you need to make x so that e^(-x/9) that is less than 0.1?

I tried inputting values for x and I came up with 21 as the value for x.
Found 2 solutions by stanbon, josmiceli:
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
make x so that e^(-x/9) that is less than 0.1
--------------------
e^(-x/9)< 0.1
Take the natural log of both sides to get:
-(x/9) = ln(0.1)
-(x/9) < -2.3026
Multiply both sides by -1 to switch the inequality:
x/9> 2.3026
Multiply both sides by 9 to get:
x>20.7233
Cheers,
Stan H.
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!

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