Question

How do you solve `5^(x-3) = 21`?

Answer 1

`x=ln21/ln5 +3~~4.89`

Explanation:

`ln 5^(x-3)=ln21`

Use Property `log_bx^n=nlog_bx`

`(x-3) ln5=ln21`

`x-3=ln21/ln5`

`x=ln21/ln5 +3~~4.89`