В 1. Решите систему уравнений {1/х+1/у = 3 { ху=2

1/x+1/y=1/3

xy=-18⇒x=-18/y

-y/18+1/y=1/3

-y²+18=6y

y²+6y-18=0

D=36*72=108 √D=6√3

y1 = (-6-6√3) / 2=-3-3√3⇒x1=-18 / (-3-3√3) = 6 / (1+√3) = 6 (-1+√3) / (1-3) = 3 (1-√3)

y2 = (-6+6√3) / 2=-3+3√3⇒x2=-18 / (-3+3√3) = 6 / (1-√3) = 6 (1+√3) / (1-3) = - 3 (√3+1)