How could I explain the unit rate in the context of the problem?

The weight v of an object on venus varies directly with its weight e on earth. a person weighing 120 lb on earth would weigh 106 lb on venus. how much would a person weighing 150 lb on earth weigh on venus?

The volume of a box varies directly with its length if a box in the group has a length of 30inches and k=24 what is its volume

Solve the following: 12(x^2–x–1)+13(x^2–x–1)=25(x^2–x–1) 364x–64x=300x