Question

how do i find range of values of x for which 100e^-x<5

Answer 1

\[100e^{-x}<5\\
e^{-x}<1/20\\
-x<\ln(1/20)\\
x>-\ln(1/20)\\
x>\ln(20)\]

Answer 2

do you understand it why ?

Answer 3

yes thank you I understand. Because the question said range I thought there should be more than one answer for x. thanks