r^2-2r+1800=0

Solution for r^2-2r+1800=0 equation:

Simplifying
r2 + -2r + 1800 = 0

Reorder the terms:
1800 + -2r + r2 = 0

Solving
1800 + -2r + r2 = 0

Solving for variable 'r'.

Begin completing the square.

Move the constant term to the right:

Add '-1800' to each side of the equation.
1800 + -2r + -1800 + r2 = 0 + -1800

Reorder the terms:
1800 + -1800 + -2r + r2 = 0 + -1800

Combine like terms: 1800 + -1800 = 0
0 + -2r + r2 = 0 + -1800
-2r + r2 = 0 + -1800

Combine like terms: 0 + -1800 = -1800
-2r + r2 = -1800

The r term is -2r.  Take half its coefficient (-1).
Square it (1) and add it to both sides.

Add '1' to each side of the equation.
-2r + 1 + r2 = -1800 + 1

Reorder the terms:
1 + -2r + r2 = -1800 + 1

Combine like terms: -1800 + 1 = -1799
1 + -2r + r2 = -1799

Factor a perfect square on the left side:
(r + -1)(r + -1) = -1799

Can't calculate square root of the right side.

The solution to this equation could not be determined.