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Solve -4x² = 5x + 9. *a x=-1 or x=-1/4 x=-1 or x = 9/4 x= 2 or x= 3 No real solutions

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4 votes

Answer:

No real solutions

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

Algebra I

  • Standard Form: ax² + bx + c = 0
  • Quadratic Formula:
    x=(-b\pm√(b^2-4ac) )/(2a)

Algebra II

  • Imaginary Numbers: √-1 = i

Explanation:

Step 1: Define

-4x² = 5x + 9

Step 2: Rewrite

Find standard form.

  1. Subtract 5x on both sides: -4x² - 5x = 9
  2. Subtract 9 on both sides: -4x² - 5x - 9 = 0

Step 3: Identify Variables

a = -4

b = -5

c = -9

Step 4: Solve for x

  1. Substitute [QF]:
    x=(5\pm√((-5)^2-4(-4)(-9)) )/(2(-4))
  2. Exponents:
    x=(5\pm√(25-4(-4)(-9)) )/(2(-4))
  3. Multiply:
    x=(5\pm√(25-144) )/(-8)
  4. Subtract:
    x=(5\pm√(-119) )/(-8)
  5. Factor:
    x=(5\pm√(-1) √(119) )/(-8)
  6. Simplify:
    x=(5\pm i√(119) )/(-8)

Here we see that we get imaginary numbers.

∴ the quadratic would have no real roots.

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