The work of a student to solve the equation 4(3x − 4) = 8 + 4x + 8 is shown below:
Step 1. 4(3x − 4) = 8 + 4x + 8
Step 2. 7x − 8 = 16 + 4x
Step 3. 7x − 4x = 16 + 8
Step 4. 3x = 24
Step 5. x = 8
In which step did the student first make an error and what is the correct step?
A. Step 2, 12x − 16 = 16 + 4x
B. Step 2, 12x − 8 = 2(4 + 2x + 4)
C. Step 3, 7x − 4x = 16 − 8
D. Step 3, 7x + 4x = 16 + 8
