The steps below show the incomplete solution to find the value of q for the equation 4q - 2q - 4 = -1 + 21

Step 1: 4q - 2q - 4 = -1 + 21

Step 2: 4q - 2q - 4 = 20

Step 3: 2q - 4 = 20

Which of these is most likely the next step?