Yeah, it's a poor formulation although the intent can be figured out if you focus hard enough but let me make it easier.
> We can use tax allowances instead of actual car expenses because you can be sure the taxman won't allow you to deduct more than what you are spending so the earnings we calculate here will not be more than the actual.
> We can use tax allowances instead of actual car expenses because you can be sure the taxman won't allow you to deduct more than what you are spending so the earnings we calculate here will not be more than the actual.
As a formula:
#1: (actual car expenses) <= (tax allowances)
Adding (total uber fees)
#2: (total uber fees) - (actual expenses) <= (total uber fees) - (tax allowances)
and then we go on to prove
#3: (total uber fees) - (tax allowances) < minimal wage
And so:
#4: (total uber fees) - (actual expenses) < minimal wage
Changing <= to = (as you suggest) in #1 and #3 doesn't change the logic of our proof.