Question

-х^2-20х+56=0

Пожалуйста)

Answer 1

-x^2-20x+56=0
x^2+20x-56=0
k=b/2=20/2=10

D/4 = k^2-ac=100+56=156

x1= -k+√D= -10+√156=-10+2√39
x2= -k-√D=-10-2√39 

 

Answer 2

-х^2-20х+56=0
D=400-224=176
x1=-10+2/^39
х2=-10-2/^39