An equation and the steps to solve it are shown below:

7x − one over two (8x + 4) = 6

Step 1: 7x − 4x − 2 = 6
Step 2: 3x − 2 = 6
Step 3: 3x − 2 + 2 = 6
Step 4: 3x = 6
Step 5: x = 2

Which step was the error made and why?