А) x (x-15) = 16 решите уравнение

Х (х - 15) = 16

х^2 - 15 х = 16

х^2 - 15 х - 16 = 0

D = b^2 - 4 * a * c = - 15^2 - 4 * 1 * (-16) = 225 + 64 = 289

x1/2 = (-b + / - √D) / (2 * a)

x1/2 = ( - (-15) + / - 17) / (2 * 1)

x1/2 = (15 + / - 17) / 2

x1 = (15 + 17) / 2

x1 = 32/2

x1 = 16

x2 = (15 - 17) / 2

x2 = - 2/2

x2 = - 1.