First arrange numbers
14,15,15,17,19,20,21,23,24
19 is median
15+15/2=15 is first quartile
You can figure out what four times eight is by adding eight and eight(16) and doubling it (32)
7 is the right answer(please rate 5.0 stars so i can help other people out thanks)
Answer: 2(x + 4)(x - 4)
Hope this helped!