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x^2-8x+15=0 solve the equation by completing the square. Round your solutions to the nearest hundredth, if necessary.

1 Answer

3 votes

Answer:

x = 3, 5

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

  1. Brackets
  2. Parenthesis
  3. Exponents
  4. Multiplication
  5. Division
  6. Addition
  7. Subtraction
  • Left to Right

Equality Properties

  • Multiplication Property of Equality
  • Division Property of Equality
  • Addition Property of Equality
  • Subtract Property of Equality

Algebra I

  • Terms/Coefficients/Degrees
  • Standard Form: ax² + bx + c = 0
  • Multiple Roots
  • Factoring
  • Completing the Square: -b/(2a)

Explanation:

Step 1: Define

x² - 8x + 15 = 0

Step 2: Solve for x

  1. [Subtraction Property of Equality] Subtract 15 on both sides: x² - 8x = -15
  2. Complete the Square [Addition Property of Equality]: x² - 8x + 16 = -15 + 16
  3. [Complete the Square] Simplify: (x - 4)² = 1
  4. [Equality Property] Square root both sides: x - 4 = ±1
  5. [Addition Property of Equality] Add 4 on both sides: x = 4 ± 1
  6. Evaluate: x = 3, 5
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