Question 418948: Solve by completing the square
x^2+9x+20=0 and can you show me how you got that
Answer by scott8148(6628)   (Show Source):
You can put this solution on YOUR website! subtracting 20 ___ x^2 + 9x = -20
when the coefficient of the squared term is one (as in this case)
___ take half of the 1st order coefficient , square the quantity , add to both sides of equation
x^2 + 9x + (9/2)^2 = -20 + (9/2)^2
[x + (9/2)]^2 = -(80/4) + (81/4)
x + (9/2) = sqrt(1/4)
x = -(9/2) ± (1/2)
x = -5 ___ and ___ x = -4
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