800=X(-2X+1)

Solution for 800=X(-2X+1) equation:

Simplifying
800 = X(-2X + 1)

Reorder the terms:
800 = X(1 + -2X)
800 = (1 * X + -2X * X)
800 = (1X + -2X2)

Solving
800 = 1X + -2X2

Solving for variable 'X'.

Reorder the terms:
800 + -1X + 2X2 = 1X + -1X + -2X2 + 2X2

Combine like terms: 1X + -1X = 0
800 + -1X + 2X2 = 0 + -2X2 + 2X2
800 + -1X + 2X2 = -2X2 + 2X2

Combine like terms: -2X2 + 2X2 = 0
800 + -1X + 2X2 = 0

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

Divide each side by '2'.
400 + -0.5X + X2 = 0

Move the constant term to the right:

Add '-400' to each side of the equation.
400 + -0.5X + -400 + X2 = 0 + -400

Reorder the terms:
400 + -400 + -0.5X + X2 = 0 + -400

Combine like terms: 400 + -400 = 0
0 + -0.5X + X2 = 0 + -400
-0.5X + X2 = 0 + -400

Combine like terms: 0 + -400 = -400
-0.5X + X2 = -400

The X term is -0.5X.  Take half its coefficient (-0.25).
Square it (0.0625) and add it to both sides.

Add '0.0625' to each side of the equation.
-0.5X + 0.0625 + X2 = -400 + 0.0625

Reorder the terms:
0.0625 + -0.5X + X2 = -400 + 0.0625

Combine like terms: -400 + 0.0625 = -399.9375
0.0625 + -0.5X + X2 = -399.9375

Factor a perfect square on the left side:
(X + -0.25)(X + -0.25) = -399.9375

Can't calculate square root of the right side.

The solution to this equation could not be determined.