How do you solve q^2+11q+1=-9 by completing a square?

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Answer 1

Hi Lilian,

 

q^2 + 11q + 1 = -9

Move the constant to the right side.

q^2 + 11q = -10

Add the square of b/2 to both sides. b =11

q^2 + 11q + (11/2)^2 = -10 + (11/2)^2

(q + 11/2)^2 = 81/4

q + 11/2 = +/- 9/2

q + 11/2 = 9/2

q = -2/2

= -1

q + 11/2 = - 9/2

q = -20/2

= -10

q = {-10, -1}