10x^2-4x=-21

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Solution for 10x^2-4x=-21 equation:


Simplifying
10x2 + -4x = -21

Reorder the terms:
-4x + 10x2 = -21

Solving
-4x + 10x2 = -21

Solving for variable 'x'.

Reorder the terms:
21 + -4x + 10x2 = -21 + 21

Combine like terms: -21 + 21 = 0
21 + -4x + 10x2 = 0

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

Divide each side by '10'.
2.1 + -0.4x + x2 = 0

Move the constant term to the right:

Add '-2.1' to each side of the equation.
2.1 + -0.4x + -2.1 + x2 = 0 + -2.1

Reorder the terms:
2.1 + -2.1 + -0.4x + x2 = 0 + -2.1

Combine like terms: 2.1 + -2.1 = 0.0
0.0 + -0.4x + x2 = 0 + -2.1
-0.4x + x2 = 0 + -2.1

Combine like terms: 0 + -2.1 = -2.1
-0.4x + x2 = -2.1

The x term is -0.4x.  Take half its coefficient (-0.2).
Square it (0.04) and add it to both sides.

Add '0.04' to each side of the equation.
-0.4x + 0.04 + x2 = -2.1 + 0.04

Reorder the terms:
0.04 + -0.4x + x2 = -2.1 + 0.04

Combine like terms: -2.1 + 0.04 = -2.06
0.04 + -0.4x + x2 = -2.06

Factor a perfect square on the left side:
(x + -0.2)(x + -0.2) = -2.06

Can't calculate square root of the right side.

The solution to this equation could not be determined.

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