Question

Найдите корни уравнения х^2–7х=8

Answer 1

x^2  - 7x - 8 =  0
D  = 49 + 4*8 = 81 = 9^2
x1 = ( 7 + 9)/2 = 16/2 = 8
x2 = ( 7 - 9)/2  =  - 2/2 = - 1

Answer 2

x^2-7x-8=0

Answer 3

правильно

Answer 4

 х^2–7х=8
 х^2–7х-8=0
D = b^2 - 4ac = (-7)^2 - 4 * 1 * (-8) = 49 + 32 = 81
Х1 = (-b + √D)/ 2a =  (7+9)/2 = 16/2 = 8
Х2 = (-b - √D)/ 2a = (7-9)/2 = -2/2 = -1
Х1 = 8; Х2 = -1