solve these magic squares using positive and negative numbers equal and he shown number. use 0 if u have to as well

The floor plan of a room has a scale of 2.5 in.: 35 ft. in the drawing, the length of the room is 8 in. and the width of the room is 6 in. what is the perimeter of the actual room?

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

Given that ot =5, xt=12, and ox= 13 is xy tangent to circle o at t? explain.