R:{(2,0),(1,1)}
(1) (3 + X) (4 + Y) =20
(2) X+Y=2? =>x=2-y
(1)12+3y+4x+xy=20
4x+3y+xy=8
4(2-y)+3y+(2-y)y=8
8-4y+3y+2y-y²-8=0
-y²-y=0
y²+y=0
y(y+1)=0
y'=0
y"=-1
Para y=0;
x+y=2=>x=2
Para y=-1;
x=2+1=> x=3
S={(2;0);(3;-1)}
#
y 3+x3-3-1=2
e 1+1=3
Comments
(1) (3 + X) (4 + Y) =20
(2) X+Y=2? =>x=2-y
(1)12+3y+4x+xy=20
4x+3y+xy=8
4(2-y)+3y+(2-y)y=8
8-4y+3y+2y-y²-8=0
-y²-y=0
y²+y=0
y(y+1)=0
y'=0
y"=-1
Para y=0;
x+y=2=>x=2
Para y=-1;
x=2+1=> x=3
S={(2;0);(3;-1)}
#
y 3+x3-3-1=2
e 1+1=3