How do you solve e^(-x) = 5^(2x) ?

1 Answer
Dec 13, 2015

Apply properties of logarithms to find that x=0

Explanation:

We will use the following properties:

  • ln(a^x) = xln(a)

  • ln(e) = 1


e^(-x) = 5^(2x)

=> ln(e^(-x)) = ln(5^(2x))

=> -xln(e) = 2xln(5)

=> -x = 2ln(5)x

=> 2ln(5)x+x = 0

=> x(2ln(5)+1) = 0

=> x = 0