Question

Ciara solves the exponential equation 3^x+1 = 15 and her work is shown below. What is the first step she did incorrectly?

Answer 1

`3^(x+1)=15`

Step 1:

`\log (3^(x+1))=\log (15)`

She took the log base 10 of both sides. This is correct.

Step 2:

`(x+1)\log (3)=\log (15)`

She applied the power rule. This is correct.

Step 3:

`\log (3)=(\log (15))/(x+1)`

She divided both sides by x + 1. Actually she didn't do anything incorrectly, basically, she took a longer way to solve it. In this step, she should have divided both sides by log(3), that would made the task much shorter. So we can conclude, that the first step she did incorrectly was step 3