Question

How do you solve `5^(-t/2)=0.20`?

Answer 1

`t=2`

Explanation:

`5^(-t/2)=0.2`

see if RHS can be expressed as a power of `" "5`
change RHS to a fraction

`5^(-t/2)=1/5`

`5^(-t/2)=5^(-1)`

`=>t/2=1`

`:.t=2`