x-y=7
xy=-10
x=7+y
(7+y)y=-10
y^2+7y+10=0
(y+2)(y+5)=0
y+2=0 или y+5=0
y=-2 x=7+y=7-2=5
y=-5 x=7-5=-2
ответ (5;-2), (-2;5)
xy=-12
(7+y)y=-12
y^2+7y+12=0
(y+3)(y+4)=0
y+3=0 или y+4=0
y=-3 x=7+y=7-3=4
y=-4 x=7+y=7-4=3
ответ: (4;-3), (3;-4)
x-y=7
xy=-10
x=7+y
(7+y)y=-10
y^2+7y+10=0
(y+2)(y+5)=0
y+2=0 или y+5=0
y=-2 x=7+y=7-2=5
y=-5 x=7-5=-2
ответ (5;-2), (-2;5)
x-y=7
xy=-12
x=7+y
(7+y)y=-12
y^2+7y+12=0
(y+3)(y+4)=0
y+3=0 или y+4=0
y=-3 x=7+y=7-3=4
y=-4 x=7+y=7-4=3
ответ: (4;-3), (3;-4)