Solving the Equation x² – 24x + 80 by Completing the Square
To solve the quadratic equation x² – 24x + 80 = 0 by completing the square, follow these steps:
- Rearrange the equation: Start with the original equation:
x² - 24x + 80 = 0
- Move the constant term (80) to the other side:
x² - 24x = -80
- Determine the value to complete the square: Take half of the coefficient of x (which is -24), square it, and add it to both sides:
Half of -24 is -12. Squaring -12 gives 144.
- Add 144 to both sides:
x² - 24x + 144 = -80 + 144
This simplifies to:
x² - 24x + 144 = 64
- Factor the left-hand side:
(x - 12)² = 64
- Take the square root of both sides:
x - 12 = ±8
- Solve for x:
- For x – 12 = 8:
x = 8 + 12 = 20
- For x – 12 = -8:
x = -8 + 12 = 4
- For x – 12 = 8:
Conclusion
The solution set of the equation x² – 24x + 80 = 0 is:
{4, 20}