Question

Solve 9x + 4 = 11 for x using the change of base formula log base b of y equals log y over log b

Answer 1

`x = (7)/(9)`

Explanation:

`9x = 7 \\ (9x)/(9) = (7)/(9) \\ x = (7)/(9)`

Answer 2

`x=0.885622`

Explanation:

Given that an exponential equation in x as

`9^x + 4 = 11`

We have to solve for x using change of base formula for log

Subtract 4 from both the sides

`9^x =7`

Take log to base 9

`x=log_9 7`

Using change of base to 10 we have

`x=(log 7)/(log 9)` taking same to base 10 by using change of base formula

`x=0.885622`