# How do you solve for x in #6 = 15^(1-x)#?

##### 1 Answer

May 2, 2016

Use logs to calculate:

#### Explanation:

The variable is in the index and 6 is definitely not a power of 15, therefore logs are called for...

Log both sides:

Power law: #log 6 = (1-x) log 15

isolate (1-x):

With a calculator:

```
#0.338 = x#
```