Question

Introduction to quadratic equations?
If you solve the equation by completing the square, fill in the blanks.
9x^2+9x+4=0
x^2+x+blank=-4/9+blank <---- (blank one, both the same)

(x+1/2)^2=blank
x+1/2= ± √blank <------ blank 2(both the same)

x=-1/2 ±blank i <---- blank 3

enter blank 1, blank 2, blank 3 as common fractions separated by commas

Answer 1

x^2 + x + 1/4 = -4/9 + 1/4

(x+1/2)^2 = -7/36
x+1/2 = ± √(-7/36)

x = -1/2 ± √7/6 i

Answer 2

Andy wants the greatest possible harvest from his apple orchard. The orchard contains 220 dwarf trees per acre now, and Andy harvests, on the average, 1300 apples per tree. Because his trees are planted in rows of 10, he adds or removes trees only in groups of 10. Andy's research has shown that for every additional 10 trees he plants per acre, the average yield per tree in the orchard will decrease by 50 apples. How many trees per acre should the orchard contain to produce the maximum harvest?