Final answer:
To solve for x, use the quadratic formula by substituting the values of a, b, and c from Equation 21.3.
Step-by-step explanation:
The quadratic equation is a second-degree polynomial equation in a single variable, typically written in the form ax^2 + bx + c = 0. To find the value of x, we can use the quadratic formula, which is:
x = (-b ± √(b^2 - 4ac)) / (2a)
Given that we have Equation 21.3, we can substitute the values of a, b, and c into the quadratic formula to solve for x.