Question

как узнать квадратный корень?

Answer 1

$ax + bx + c = 0 \\ d = b {}^{2} - 4ac \\ x1 = \frac{ - b - \sqrt{d} }{2} \\ x2 = \frac{ - b + \sqrt{d} }{2a}$

Answer 2

$ax + bx + c = 0 \\ d = b {}^{2} - 4ac \\ x1 = \frac{ - b - \sqrt{d} }{2} \\ x2 = \frac{ - b + \sqrt{d} }{2a}$