-4x^2+4x+15=20

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Solution for -4x^2+4x+15=20 equation:


Simplifying
-4x2 + 4x + 15 = 20

Reorder the terms:
15 + 4x + -4x2 = 20

Solving
15 + 4x + -4x2 = 20

Solving for variable 'x'.

Reorder the terms:
15 + -20 + 4x + -4x2 = 20 + -20

Combine like terms: 15 + -20 = -5
-5 + 4x + -4x2 = 20 + -20

Combine like terms: 20 + -20 = 0
-5 + 4x + -4x2 = 0

Begin completing the square.  Divide all terms by
-4 the coefficient of the squared term: 

Divide each side by '-4'.
1.25 + -1x + x2 = 0

Move the constant term to the right:

Add '-1.25' to each side of the equation.
1.25 + -1x + -1.25 + x2 = 0 + -1.25

Reorder the terms:
1.25 + -1.25 + -1x + x2 = 0 + -1.25

Combine like terms: 1.25 + -1.25 = 0.00
0.00 + -1x + x2 = 0 + -1.25
-1x + x2 = 0 + -1.25

Combine like terms: 0 + -1.25 = -1.25
-1x + x2 = -1.25

The x term is -1x.  Take half its coefficient (-0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
-1x + 0.25 + x2 = -1.25 + 0.25

Reorder the terms:
0.25 + -1x + x2 = -1.25 + 0.25

Combine like terms: -1.25 + 0.25 = -1
0.25 + -1x + x2 = -1

Factor a perfect square on the left side:
(x + -0.5)(x + -0.5) = -1

Can't calculate square root of the right side.

The solution to this equation could not be determined.

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