-x^2+4x=9

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Solution for -x^2+4x=9 equation:


Simplifying
-1x2 + 4x = 9

Reorder the terms:
4x + -1x2 = 9

Solving
4x + -1x2 = 9

Solving for variable 'x'.

Reorder the terms:
-9 + 4x + -1x2 = 9 + -9

Combine like terms: 9 + -9 = 0
-9 + 4x + -1x2 = 0

Begin completing the square.  Divide all terms by
-1 the coefficient of the squared term: 

Divide each side by '-1'.
9 + -4x + x2 = 0

Move the constant term to the right:

Add '-9' to each side of the equation.
9 + -4x + -9 + x2 = 0 + -9

Reorder the terms:
9 + -9 + -4x + x2 = 0 + -9

Combine like terms: 9 + -9 = 0
0 + -4x + x2 = 0 + -9
-4x + x2 = 0 + -9

Combine like terms: 0 + -9 = -9
-4x + x2 = -9

The x term is -4x.  Take half its coefficient (-2).
Square it (4) and add it to both sides.

Add '4' to each side of the equation.
-4x + 4 + x2 = -9 + 4

Reorder the terms:
4 + -4x + x2 = -9 + 4

Combine like terms: -9 + 4 = -5
4 + -4x + x2 = -5

Factor a perfect square on the left side:
(x + -2)(x + -2) = -5

Can't calculate square root of the right side.

The solution to this equation could not be determined.

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