so the actual meal was at most 130 dollars they paid minus the 20 dolars tip: 130-20=110 dollars.
it was 5 people: Dolores+5 friends, who presumably all paid the same (buffet).
then we have to divide the 110 among the 5 people: it's 110/5=22
so each of them paid at most 22 dollars:
x (the amount they paid)≤22