9x^2+8x+21=0

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Solution for 9x^2+8x+21=0 equation: 


Simplifying
9x2 + 8x + 21 = 0

Reorder the terms:
21 + 8x + 9x2 = 0

Solving
21 + 8x + 9x2 = 0

Solving for variable 'x'.

Begin completing the square.  Divide all terms by
9 the coefficient of the squared term: 

Divide each side by '9'.
2.333333333 + 0.8888888889x + x2 = 0

Move the constant term to the right:

Add '-2.333333333' to each side of the equation.
2.333333333 + 0.8888888889x + -2.333333333 + x2 = 0 + -2.333333333

Reorder the terms:
2.333333333 + -2.333333333 + 0.8888888889x + x2 = 0 + -2.333333333

Combine like terms: 2.333333333 + -2.333333333 = 0.000000000
0.000000000 + 0.8888888889x + x2 = 0 + -2.333333333
0.8888888889x + x2 = 0 + -2.333333333

Combine like terms: 0 + -2.333333333 = -2.333333333
0.8888888889x + x2 = -2.333333333

The x term is 0.8888888889x.  Take half its coefficient (0.4444444445).
Square it (0.1975308642) and add it to both sides.

Add '0.1975308642' to each side of the equation.
0.8888888889x + 0.1975308642 + x2 = -2.333333333 + 0.1975308642

Reorder the terms:
0.1975308642 + 0.8888888889x + x2 = -2.333333333 + 0.1975308642

Combine like terms: -2.333333333 + 0.1975308642 = -2.1358024688
0.1975308642 + 0.8888888889x + x2 = -2.1358024688

Factor a perfect square on the left side:
(x + 0.4444444445)(x + 0.4444444445) = -2.1358024688

Can't calculate square root of the right side.

The solution to this equation could not be determined.

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