What is 3.25 x 10^4 as an ordinary number

Write two subtraction equations that are equivalent to 5 + 12 = 17.

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?

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.