21x^2+5x+7=0

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Solution for 21x^2+5x+7=0 equation:


Simplifying
21x2 + 5x + 7 = 0

Reorder the terms:
7 + 5x + 21x2 = 0

Solving
7 + 5x + 21x2 = 0

Solving for variable 'x'.

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

Divide each side by '21'.
0.3333333333 + 0.2380952381x + x2 = 0

Move the constant term to the right:

Add '-0.3333333333' to each side of the equation.
0.3333333333 + 0.2380952381x + -0.3333333333 + x2 = 0 + -0.3333333333

Reorder the terms:
0.3333333333 + -0.3333333333 + 0.2380952381x + x2 = 0 + -0.3333333333

Combine like terms: 0.3333333333 + -0.3333333333 = 0.0000000000
0.0000000000 + 0.2380952381x + x2 = 0 + -0.3333333333
0.2380952381x + x2 = 0 + -0.3333333333

Combine like terms: 0 + -0.3333333333 = -0.3333333333
0.2380952381x + x2 = -0.3333333333

The x term is 0.2380952381x.  Take half its coefficient (0.1190476191).
Square it (0.01417233561) and add it to both sides.

Add '0.01417233561' to each side of the equation.
0.2380952381x + 0.01417233561 + x2 = -0.3333333333 + 0.01417233561

Reorder the terms:
0.01417233561 + 0.2380952381x + x2 = -0.3333333333 + 0.01417233561

Combine like terms: -0.3333333333 + 0.01417233561 = -0.31916099769
0.01417233561 + 0.2380952381x + x2 = -0.31916099769

Factor a perfect square on the left side:
(x + 0.1190476191)(x + 0.1190476191) = -0.31916099769

Can't calculate square root of the right side.

The solution to this equation could not be determined.

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