Answer :
From the starting balance(x) , we have x+34 (+$34) and then (x+34)-67. Let's say x=10. On the first equation, x+34, we now have 10+34=44. On the second equation, we have (x+34)-67, (10+34)-67= -23. From 10 (the starting balance) to 44 have 34. From 10 to -23 we have -33. The the greatest change from the starting point was on the first week, by $34.