Quadratic formula x = (-b ± √(b² - 4ac))/(2a) solves any quadratic ax² + bx + c = 0. Steps: (1) Identify a, b, c coefficients; (2) Calculate discriminant b² - 4ac; (3) Substitute into formula; (4) Simplify ± to get two roots. Example: 2x² + 3x - 2 = 0. Here a=2, b=3, c=-2. Δ = 9 + 16 = 25. x = (-3 ± 5)/4 → x = 1/2 or x = -2. Advantages: Works for all quadratics; no factorization needed. Shortcut: Memorize formula; practice substitution. Exam tip: Common mistakes: forgetting ± sign, arithmetic errors in Δ. Always simplify √Δ fully (simplify radicals). Verify by substitution.