The correct form of the quadratic formula is:

A. $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$

This formula is used to solve quadratic equations of the form $ax^2 + bx + c = 0$, where:

• $a$, $b$, and $c$ are coefficients.
• $\pm$ means there are two solutions: one with a plus and one with a minus.
• The expression $b^2 - 4ac$ is called the discriminant, which determines the nature of the roots.

Would you like more details on how to apply this formula or any specific example?

Here are 5 related questions:

1. How do you use the discriminant to determine the number of solutions?
2. What are the possible types of roots based on the discriminant?
3. Can the quadratic formula be used for any quadratic equation?
4. What happens if the discriminant is negative?
5. How do you derive the quadratic formula?

Tip: Always check the value of the discriminant before calculating the roots to know if they are real or complex.