Show work Plss o

22.5 mins

Step-by-step explanation:

To find what that video's length must be, subtract the previous videos' lengths from the requirement, 5 hours. (x is the video length of her fourth video)

7/8 + 1 1/4 + 2 1/2 + x = 5

To make adding these fractions easier, find a common denominator.

7/8 + 1 2/8 + 2 4/8 + x = 5

4 5/8 + x = 5

x = 3/8, or 22.5 minutes.

Step-by-step explanation:

Her first three videos totalled up to

hours. To meet the hour goal the shortest fouth video she can make is hours, because if the fourth video was any shorter, she'd end up with less than hours in total (this is called a proof by contradiction). We are now done.

12/11c

or

12

c

11