Richie wants to enlarge the square deck in his backyard. The area of the enlarged deck, A(x), can be modeled by the following function, where x is a side length in feet of the original square deck. What is the minimum potential area of the enlarged deck?
A= x^2-14x+106
A.
57 feet
B.
14 feet
C.
49 feet
D.
106 feet