Mathematics for IGCSE & O level - Equations (Section 6 - No. 6)

Which of the following is the correct formula to find the roots of the quadratic equation ax² + bx + c = 0?

x = (-b ± √(b² - 4ac)) / 2a

x = (b ± √(b² - 4ac)) / 2a

x = (-b ± √(b² + 4ac)) / 2a

x = (-b + √(b² - 4ac)) / a

This is the quadratic formula.