Question

решите уравнение -х^2 -8х-15=0

Answer 1

-x^2 - 8x - 15 = 0 | * (-1)
x^2  + 8x + 15 = 0
D = 8^2 - 4*15  = 64 - 60  = 4
√4 = 2
x_1 = (-8+2)/2 = -6/2 = -3
x_2 = (-8-2)/2 = -10/2 = -5