Solving Quadratic Equations Using Four Methods
Method 1: Factoring
When your equation is simple, factoring is your go-to method. First, put your equation in standard form (ax² + bx + c = 0). Then, find two numbers that add up to b and multiply to c. For example, with x² + 5x + 6 = 0, we factor to get x+3x+2 = 0, giving us solutions x = -3 and x = -2.
Method 2: Taking the Square Root
This method works great when your equation is in vertex form. Rewrite the equation as ax+b² = c, then take the square root of both sides (remember to include ±). For example, with 2x² - 5x + 3 = 0, we can transform it and find that x = 5/4 ± √2/4, giving us two solutions.
Method 3: Completing the Square
This method helps transform messy equations into something more manageable. Start with ax² + bx = c, then add b/2² to both sides to create a perfect square trinomial. For a problem like 3x² - 8x + 4 = 0, we rearrange, add the right value, and solve to get our answers.
Method 4: Quadratic Formula
The most powerful method works for any quadratic equation. Simply identify the values of a, b, and c, then plug them into the formula x = −b±√(b2−4ac)/2a. This is the Swiss Army knife of quadratic solving - it always works!
Pro Tip: Always check your answers by plugging them back into the original equation. This simple step can save you from careless mistakes on tests!