Offset means “balanced” or “cancelled out” by something else. This is especially important in finance, management etc and as a part of any evaluation of advantages and disadvantages. So, it’s useful in many of the assignments you have to do here. You can say, for instance, that negative effects in one area are offset by positive effects in another. But if positive effects are completely cancelled out by negative ones, it’s better to use ‘negate’.
The lower salaries in the suburbs are offset by the much lower cost of living.