1. **Problem:** You want to know how to do a quadratic equation.
2. A quadratic equation is usually written as $$ax^2+bx+c=0$$ where $a\neq 0$.
3. The three most common ways to solve it are factoring, using the quadratic formula, or completing the square.
4. **Factoring rule:** If you can write the quadratic as $$ax^2+bx+c=(px+q)(rx+s)$$ then set each factor equal to $0$.
5. **Key zero-product rule:** If $$AB=0$$ then $A=0$ or $B=0$.
6. Example with factoring: solve $$x^2+5x+6=0$$.
7. Factor the expression: $$x^2+5x+6=(x+2)(x+3)$$.
8. Set each factor equal to $0$: $$x+2=0$$ or $$x+3=0$$.
9. Solve each one: $$x=-2$$ or $$x=-3$$.
10. **Quadratic formula rule:** For $$ax^2+bx+c=0$$, the solutions are $$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$$.
11. The part under the square root, $$b^2-4ac$$, is called the discriminant.
12. If the discriminant is positive, there are 2 real solutions.
13. If it is zero, there is 1 real solution.
14. If it is negative, there are no real solutions.
15. Example with the formula: solve $$2x^2+3x-2=0$$.
16. Identify the values: $a=2$, $b=3$, $c=-2$.
17. Substitute into the formula: $$x=\frac{-3\pm\sqrt{3^2-4(2)(-2)}}{2(2)}$$.
18. Simplify inside the square root: $$x=\frac{-3\pm\sqrt{9+16}}{4}$$.
19. Continue simplifying: $$x=\frac{-3\pm\sqrt{25}}{4}$$.
20. So $$x=\frac{-3\pm 5}{4}$$.
21. Split into two answers: $$x=\frac{-3+5}{4}$$ and $$x=\frac{-3-5}{4}$$.
22. Final answers: $$x=\frac{1}{2}$$ and $$x=-2$$.
23. **Completing the square rule:** Rewrite the quadratic so one side becomes a perfect square trinomial.
24. This method is useful when factoring is hard.
25. A simple plan is: move the constant, make the $x^2$ coefficient $1$ if needed, take half of $b$, square it, then add it to both sides.
26. **Best habit:** Always check your answer by substituting it back into the original equation.
27. If you want, I can also show you how to solve one specific quadratic step by step.
Quadratic Equation D8C7D7
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.