Gente quanto é g)3x=12 h)9x=18 i)35x=-105 j)7x-1=13 e a letra a b c etc eu já fiz

What is the missing constant term in the perfect square that starts with x^2 -20x

The weight of an object in a particular scale is 175.2 lbs. the measured weight may vary from the actual weight by at most 0.1 lbs. what is the range of actual weights of the object

Plz help plz give me the answer