Each product is in the form ax2 + bx + c. (x + 3)2 = x2 + 6x + 9 (x + 4)2 = x2 + 8x + 16 (x + 5)2 = x2 + 10x + 25 (x + 6)2 = x2 + 12x + 36 which of the following describes the relationship between b and c? a: c is 1.5 times that of b. b: c is double b. c: c is the square of half of b. d: c is the square of b.