Tina pet sits to earn extra money. She charges a flat service fee of $20, plus $20 per day. If one of her customers spent less t
han $80, which of the following inequalities could be used to solve for x, the number of days the customer paid for pet sitting?a) $20x + $20 < $80b) $20x < $80c) $20x - $20 < $80d) $20x < $100
