Question

What is the solution to the equation `9^(-3x) = 7`?

Answer 1

`x~=-0.29521`

Explanation:

`9^(-3x)=7`

`-3xln9 = ln7`

`-3x= ln7/ln9`

`-3x ~= 1.94591/2.19722`

`-3x~= 0.88562`

`x ~= -0.29521`

Check:
`9^(3 * 0.29521) = 9^0.88562 ~= 7`