The area of a square garden is A square feet and the perimeter is p feet. If a=2p+15, what is the perimeter of the garden, in feet?	Answers
A) 28 B) 36 C) 40 D) 56 E) 64

Rationale: "perimeter of square = p side of square = p / 4 area of square = ( p ^ 2 ) / 16 = a given that a = 2 p + 15 ( p ^ 2 ) / 16 = 2 p + 15 p ^ 2 = 32 p + 240 p ^ 2 - 32 p - 240 = 0 p ^ 2 - 40 p + 6 p - 240 = 0 p ( p - 40 ) + 6 ( p + 40 ) = 0 ( p - 40 ) ( p + 6 ) = 0 p = 40 or - 6 discarding negative value , p = 40 answer is c"
Answer: C