r^2-3r+42=0

Solution for r^2-3r+42=0 equation:

Simplifying
r2 + -3r + 42 = 0

Reorder the terms:
42 + -3r + r2 = 0

Solving
42 + -3r + r2 = 0

Solving for variable 'r'.

Begin completing the square.

Move the constant term to the right:

Add '-42' to each side of the equation.
42 + -3r + -42 + r2 = 0 + -42

Reorder the terms:
42 + -42 + -3r + r2 = 0 + -42

Combine like terms: 42 + -42 = 0
0 + -3r + r2 = 0 + -42
-3r + r2 = 0 + -42

Combine like terms: 0 + -42 = -42
-3r + r2 = -42

The r term is -3r.  Take half its coefficient (-1.5).
Square it (2.25) and add it to both sides.

Add '2.25' to each side of the equation.
-3r + 2.25 + r2 = -42 + 2.25

Reorder the terms:
2.25 + -3r + r2 = -42 + 2.25

Combine like terms: -42 + 2.25 = -39.75
2.25 + -3r + r2 = -39.75

Factor a perfect square on the left side:
(r + -1.5)(r + -1.5) = -39.75

Can't calculate square root of the right side.

The solution to this equation could not be determined.