The work of a student to solve the equation 2(3x − 4) = 8 + 2x + 4 is shown below:

Question

Step 1: 2(3x − 4) = 8 + 2x + 4
Step 2: 5x − 6 = 12 + 2x
Step 3: 5x − 2x = 12 + 6
Step 4: 3x = 18
Step 5: x = 6

In which step did the student first make an error and what is the correct step? (5 points)

Step 2; 6x − 6 = 2(6 + x + 2)

Step 2; 6x − 8 = 12 + 2x

Step 3; 5x − 2x = 12 − 6

Step 3; 5x + 2x = 12 + 6

Answer 1

The student made an error in Step 2. The correct step is:
2(3x − 4) = 8 + 2x + 4
6x - 8 = 8 + 2x + 4