The answer is D, 77
The process is to find out the opposite of 144, which is 36, then add it with the extra 1 that is being added With 6x, then after that you subtract 37 from 180 and get 143 in the process, and then divide 143 by 13 to get 11 which is normal x, so x = 11, then you take x and multiply it by 7 and get 77, which is your answer.
