No, they have to rise by more than that. Your math is technically correct (a 6% rise gives you an extra $700 million), but you are assuming that the price increase goes entirely to Uber. There is no way Uber can increase prices by 6% and give none of that upside to their drivers - they would flee to platforms offering better terms (like Lyft).
If Uber was to be profitable this past quarter they wouldn't have needed an extra $700 million in fares, but an extra 2.3 billion - which is a 20% rise.