The steps below show the incomplete solution to find the value of x for the equation 6x − 2x − 5 = −6 + 21: step 1: 6x − 2x − 5 = −6 + 21 step 2: 6x − 2x − 5 = 15 step 3: 4x − 5 = 15 which of these is most likely the next step? 4x = 10 4x = 3 4x = 45 4x = 20