Taking log of both sides:

log 5^{x} = log 0.3

So

`log\ 5^x=log\ 0.3` `x\ log\ 5=log\ 0.3` `x=(log\ 0.3)/(log\ 5)` `=-0.748070363`

`log\ 5^x=log\ 0.3`

`x\ log\ 5=log\ 0.3`

`x=(log\ 0.3)/(log\ 5)`

`=-0.748070363`

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