Which of the following describes the correct process for solving the equation 2x − 4 = 20 and arrives at the correct solution?

add 4 to both sides, and then divide by 2. the solution is x = 12.
divide both sides by −4, and then subtract 2. the solution is x = −7.
subtract 4 from both sides, and then divide by 2. the solution is x = −12.
multiply both sides by −4, and then divide by 2. the solution is x = −40.