2r^2-5r+7=0

Solution for 2r^2-5r+7=0 equation:

Simplifying
2r2 + -5r + 7 = 0

Reorder the terms:
7 + -5r + 2r2 = 0

Solving
7 + -5r + 2r2 = 0

Solving for variable 'r'.

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

Divide each side by '2'.
3.5 + -2.5r + r2 = 0

Move the constant term to the right:

Add '-3.5' to each side of the equation.
3.5 + -2.5r + -3.5 + r2 = 0 + -3.5

Reorder the terms:
3.5 + -3.5 + -2.5r + r2 = 0 + -3.5

Combine like terms: 3.5 + -3.5 = 0.0
0.0 + -2.5r + r2 = 0 + -3.5
-2.5r + r2 = 0 + -3.5

Combine like terms: 0 + -3.5 = -3.5
-2.5r + r2 = -3.5

The r term is -2.5r.  Take half its coefficient (-1.25).
Square it (1.5625) and add it to both sides.

Add '1.5625' to each side of the equation.
-2.5r + 1.5625 + r2 = -3.5 + 1.5625

Reorder the terms:
1.5625 + -2.5r + r2 = -3.5 + 1.5625

Combine like terms: -3.5 + 1.5625 = -1.9375
1.5625 + -2.5r + r2 = -1.9375

Factor a perfect square on the left side:
(r + -1.25)(r + -1.25) = -1.9375

Can't calculate square root of the right side.

The solution to this equation could not be determined.