If Jennifer owes $192, then it's basically -192. If she makes a $25 purchase she's spending morr and going deeper into the negative side, which would be -217. If she pays $40, however, she is adding those to relieve her debt, which would be -$217+$40, which gives you - $177.
Basically, her current balance is -$177 which means she still owes the credit card company $177
