Two sets of the sum of a number and eight are added to five times the same number

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

Twenty points. suppose that one doll house uses the 1 inch scale, meaning that 1 inch on the doll house corresponds to 1/2 foot for life-sized objects. if the doll house is 108 inches wide, what is the width of the full-sized house that it's modeled after? in inches and feet

Math it's appreciated. (picture provided)