I don’t know sorry but like how’s yoonbum doing? Also like wanna be friends?
Present area = 120 * 80 = 9600 ft^2 so the new area will be 9600 + 4400 = 14000
So if increase in length = x we have
(x + 120)(x + 80) = 14,000
x^2 + 200x + 9600 - 14000 = 0
x^2 + 200x - 4400 = 0
x = 20 feet answer

Constant is the number that cannot change the value
Im not sure..but you can copy it
They will have same slopes but different Y intercepts.