Y^2 - xy = 12
3y - X = 10
Решение
Х = 3y - 10
y^2 - y( 3y - 10 ) = 12
y^2 - 3y^2 + 10y = 12
2y^2 - 10y + 12 = 0
2( y^2 - 5y + 6 ) = 0
D = 25 - 24 = 1
y1 = ( 5 + 1 ) : 2 = 3
y2 = ( 5 - 1 ) : 2 = 2
X1 = 3•3 - 10 = - 1
X2 = 3•2 - 10 = - 4
Ответ ( - 1 ; 3 ) ; ( - 4 ; 2 )