If the odds offered on a particular selection are -110, that means in order to 'win' (profit)R$100, you would need to wagerR$110. If the odds are +110, it means that if you wageredR$100, you would 'win' (profit)R$110.
The odds for favorites are accompanied by a minus (-) sign and indicate the amount you need to stake to winR$100. On the other hand, the odds for the underdogs are accompanied by a positive (+) sign and indicate the amount won for everyR$100 staked.