Question

решите систему уравнений х-у=-6 и ху=-8

Answer 1

Х - y = - 6
Xy = - 8
••••••••••••
X = y - 6
y( y - 6 ) = - 8
y^2 - 6y + 8 = 0
D = 36 - 32 = 4 = 2^2
y1 = ( 6 + 2 ) : 2 = 4
y2 = ( 6 - 2 ) : 2 = 2
X1 = 4 - 6 = - 2
X2 = 2 - 6 = - 4
Ответ ( - 2 ; 4 ) ; ( - 4 ; 2 )