Mathematics
How do you solve quadratic equations using the quadratic formula?
December 18, 2025
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Expert Answer:
The quadratic formula is x = (-b ± √(b² - 4ac)) / (2a), where a, b, and c are coefficients from the equation ax² + bx + c = 0.
Here's a step-by-step guide:
1. **Identify the coefficients**: First, ensure your equation is in standard form (ax² + bx + c = 0). Identify the values of a, b, and c.
2. **Calculate the discriminant**: The discriminant is b² - 4ac. This tells us about the nature of the roots:
- If positive: two distinct real solutions
- If zero: one repeated real solution
- If negative: two complex solutions
3. **Substitute into the formula**: Plug your values of a, b, and c into the quadratic formula.
4. **Simplify**: Calculate the value under the square root first, then divide by 2a.
**Example**: Solve 2x² + 5x - 3 = 0
- a = 2, b = 5, c = -3
- Discriminant = 5² - 4(2)(-3) = 25 + 24 = 49
- x = (-5 ± √49) / (2·2) = (-5 ± 7) / 4
- x₁ = (-5 + 7) / 4 = 2/4 = 1/2
- x₂ = (-5 - 7) / 4 = -12/4 = -3
The solutions are x = 1/2 and x = -3.
Related Topics:
#quadratic equations#algebra#formulas#mathematics