Question

Dylan solved the exponential equation 3x+1 = 15 and his work is shown below. What is the first step he did incorrectly?

Step 1: log3x+1 = log15
Step 2: 3 log(x + 1) = log15
Step 3: log(x + 1) = log 15 over 3
Step 4: log(x + 1) = 0.3920304
Step 5: ln[log(x + 1)] = ln0.3920304
Step 6: x + 1 = −0.936415
Step 7: x = −1.936415

Answer 1

He messed up in step 2

Answer 2

The answer is Step 2.

The exponential equation is: 3ˣ⁺¹ = 15.
Step 1: log3ˣ⁺¹ = log15
Step 2: (x + 1) * log3 = log15
Step 3: x + 1 = log 15 / log 3
Step 4: x + 1 = 1.18 / 0.48
Step 5: x + 1 = 2.46
Step 6: x = 2.46 - 1
Step 7: x = 1.46