452
x-y=4⇒x=y+4
x²+y²=10
y²+yy+16+y²-10=0
2y²+8y+6=0
y²+4y+3=0
y1+y2=-4 u y1*y2=3
y1=-3⇒x1=1
y2=-1⇒x2=3
(1;-3);(3;-1)
455
y-x=2⇒x=y-2
y²-4x=13
y²-4y+8-13=0
y²+4y-5=0
y1+y2=4 U y1*y2=-5
y1=-1⇒x1=-3
y2=5⇒x2=3
(-3;-1);(3;5)
458
x-y=1⇒x=y+1
xy=12
y²+y-12=0
y1+y2=-1 u y1*y2=-12
y1=-4⇒x1=-3
y2=3⇒x2=4
(-3;-4);(4;3)