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Solve x^2-2x+1=9 by completing the square

User Dnoxs
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2 Answers

20 votes
20 votes

Final answer:

The quadratic equation x^2-2x+1=9 is solved by completing the square, resulting in the two solutions x=4 and x=-2.

Step-by-step explanation:

To solve the given equation x^2-2x+1=9 by completing the square, we can follow these steps:

  1. First, move the constant term to the other side of the equation: x^2 - 2x = 8.
  2. Next, complete the square on the left side by adding and subtracting the square of half the coefficient of x, which is 1, giving us: x^2 - 2x + 1 = 8 + 1.
  3. Now, recognize the left side as a perfect square: (x - 1)^2 = 9.
  4. Take the square root of both sides of the equation, remembering to consider both the positive and negative square roots: x-1 = ±3.
  5. Finally, solve for x by adding 1 to both sides: x = 1 ± 3. So, the two solutions for x are x = 4 and x = -2.

By following these steps, we have completed the square and found the solutions to the equation x^2-2x+1=9.

User Adam Cameron
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3.0k points
16 votes
16 votes

Answer:

Step-by-step explanation:

Solve x^2-2x+1=9 by completing the square-example-1
User Jannik Buscha
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3.1k points