A group of students must collect at least $120 to Organize a science fair they already have collected $30 which graph best represents all the remaining amount of money in dollars the student should still collect to organize the science fair

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?