Question

решить систему равенст
x+y=4
xy=3

Answer 1

x = 4 - y
(4 - y)*y = 3 *

*4y - y^2 - 3 = 0 /* (-1)
y^2 - 4y + 3 = 0 
D = 16 - 12 = 4
y1 = (4 + 2)/2 = 3
y2 = (4 - 2)/2 = 1

y1 = 3
x1 = 4 - y1 = 4 - 3 = 1

y2 = 1
x2 = 4 - y2 = 4 - 1 = 3

Ответ
(1; 3 ) ; (3; 1)