# If #5^(-x) = 3#, what does #5^(3x)# equal?

##### 2 Answers

Jan 14, 2017

Jan 15, 2017

#### Explanation:

Another approach:

Recall that

#5^(3x)=(5^-x)^(-3)#

Which is useful because we know

#5^(3x)=3^-3#

Using the rule

#5^(3x)=1/3^3=1/27#