Select all of the equations that are equivalent to 27 -3=k

Bruce is getting materials for a chemistry experiment his teacher gives him a container that has 0.25 liter of liquid in it.bruce need to use 0.4 of this liquid for the experiment. how much liquid will bruce use?

Acertain volume of water contains 100000 hydrogen atoms and 50,000 oxygen atoms how many hydrogen atoms are in a volume of water containing 4 million oxygen atoms

Abox holds 500 paperclips. after a week on the teacher's desk 239 paperclips remained. how many paperclips were used?