30x-20x^2=21

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Solution for 30x-20x^2=21 equation:


Simplifying
30x + -20x2 = 21

Solving
30x + -20x2 = 21

Solving for variable 'x'.

Reorder the terms:
-21 + 30x + -20x2 = 21 + -21

Combine like terms: 21 + -21 = 0
-21 + 30x + -20x2 = 0

Begin completing the square.  Divide all terms by
-20 the coefficient of the squared term: 

Divide each side by '-20'.
1.05 + -1.5x + x2 = 0

Move the constant term to the right:

Add '-1.05' to each side of the equation.
1.05 + -1.5x + -1.05 + x2 = 0 + -1.05

Reorder the terms:
1.05 + -1.05 + -1.5x + x2 = 0 + -1.05

Combine like terms: 1.05 + -1.05 = 0.00
0.00 + -1.5x + x2 = 0 + -1.05
-1.5x + x2 = 0 + -1.05

Combine like terms: 0 + -1.05 = -1.05
-1.5x + x2 = -1.05

The x term is -1.5x.  Take half its coefficient (-0.75).
Square it (0.5625) and add it to both sides.

Add '0.5625' to each side of the equation.
-1.5x + 0.5625 + x2 = -1.05 + 0.5625

Reorder the terms:
0.5625 + -1.5x + x2 = -1.05 + 0.5625

Combine like terms: -1.05 + 0.5625 = -0.4875
0.5625 + -1.5x + x2 = -0.4875

Factor a perfect square on the left side:
(x + -0.75)(x + -0.75) = -0.4875

Can't calculate square root of the right side.

The solution to this equation could not be determined.

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