u^2-8u+42=0

Solution for u^2-8u+42=0 equation:

Simplifying
u2 + -8u + 42 = 0

Reorder the terms:
42 + -8u + u2 = 0

Solving
42 + -8u + u2 = 0

Solving for variable 'u'.

Begin completing the square.

Move the constant term to the right:

Add '-42' to each side of the equation.
42 + -8u + -42 + u2 = 0 + -42

Reorder the terms:
42 + -42 + -8u + u2 = 0 + -42

Combine like terms: 42 + -42 = 0
0 + -8u + u2 = 0 + -42
-8u + u2 = 0 + -42

Combine like terms: 0 + -42 = -42
-8u + u2 = -42

The u term is -8u.  Take half its coefficient (-4).
Square it (16) and add it to both sides.

Add '16' to each side of the equation.
-8u + 16 + u2 = -42 + 16

Reorder the terms:
16 + -8u + u2 = -42 + 16

Combine like terms: -42 + 16 = -26
16 + -8u + u2 = -26

Factor a perfect square on the left side:
(u + -4)(u + -4) = -26

Can't calculate square root of the right side.

The solution to this equation could not be determined.