Question

Нужно развязать уравнения

Answer 1

a) (y - 1)^2 - 4 = 0

(y - 1 - 2)(y - 1 + 2) = 0

(y - 3)(y + 1) = 0

y = 3     y = -1

б) x^2 - 8x + 15 = 0

D = b^2 - 4ac = 64 - 60 = 4 = 2^2

x1,2 = (-b +- √D) / 2a = (8 +- 2) / 2

x1 = (8 + 2) / 2 = 5          x2 = (8 - 2) / 2 = 3