r^2-8r+2=0

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Solution for r^2-8r+2=0 equation:


Simplifying
r2 + -8r + 2 = 0

Reorder the terms:
2 + -8r + r2 = 0

Solving
2 + -8r + r2 = 0

Solving for variable 'r'.

Begin completing the square.

Move the constant term to the right:

Add '-2' to each side of the equation.
2 + -8r + -2 + r2 = 0 + -2

Reorder the terms:
2 + -2 + -8r + r2 = 0 + -2

Combine like terms: 2 + -2 = 0
0 + -8r + r2 = 0 + -2
-8r + r2 = 0 + -2

Combine like terms: 0 + -2 = -2
-8r + r2 = -2

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

Add '16' to each side of the equation.
-8r + 16 + r2 = -2 + 16

Reorder the terms:
16 + -8r + r2 = -2 + 16

Combine like terms: -2 + 16 = 14
16 + -8r + r2 = 14

Factor a perfect square on the left side:
(r + -4)(r + -4) = 14

Calculate the square root of the right side: 3.741657387

Break this problem into two subproblems by setting 
(r + -4) equal to 3.741657387 and -3.741657387.

Subproblem 1

r + -4 = 3.741657387 Simplifying r + -4 = 3.741657387 Reorder the terms: -4 + r = 3.741657387 Solving -4 + r = 3.741657387 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '4' to each side of the equation. -4 + 4 + r = 3.741657387 + 4 Combine like terms: -4 + 4 = 0 0 + r = 3.741657387 + 4 r = 3.741657387 + 4 Combine like terms: 3.741657387 + 4 = 7.741657387 r = 7.741657387 Simplifying r = 7.741657387

Subproblem 2

r + -4 = -3.741657387 Simplifying r + -4 = -3.741657387 Reorder the terms: -4 + r = -3.741657387 Solving -4 + r = -3.741657387 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '4' to each side of the equation. -4 + 4 + r = -3.741657387 + 4 Combine like terms: -4 + 4 = 0 0 + r = -3.741657387 + 4 r = -3.741657387 + 4 Combine like terms: -3.741657387 + 4 = 0.258342613 r = 0.258342613 Simplifying r = 0.258342613

Solution

The solution to the problem is based on the solutions from the subproblems. r = {7.741657387, 0.258342613}

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