Since you have y=14 for both it’s easy! -214 is 214 blocks away from 0, 234 is 234 blocks from 0 since they are on positive and negative sides you have to add them 214+234= 448 units away
Week 24,assuming that both machines are cleaned at week 0, because multiples of 12 are 12, 24,36. And multiples of 8 are 8, 16, 24. 24 is also the LCM.