Final answer:
The general formula for a quadratic equation is ax² + bx + c = 0, and the quadratic formula used to solve it is x = √(-b ± √(b² - 4ac))/(2a).
Step-by-step explanation:
The general formula for a quadratic equation is ax²+bx+c = 0. To find the solution or roots of such an equation, the quadratic formula is used, which is expressed as x = √(-b ± √(b²-4ac))/(2a). This formula derives from completing the square in the general quadratic equation and solving for x. Quadratic expressions represent second-order polynomials, and their graphs are in the shape of a parabola. Using the quadratic formula is a reliable method to find the roots even if the quadratic equation is not easily factorable.