Which number is a factor of 21?

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Which table shows a proportional relationship between miles traveled and gas used?

Find each value of the five-number summary for this set of data. [note: type your answers as numbers. do not round.] 150, 120, 136, 180, 158, 175, 124, 162 minimum maximum median upper quartile lower quartile