Question 440536
x=2y+1
xy=1
y(2y+1)=1
2y^2+y=1
2y^2+y-1=0
2*-1=-2; 2 and -1 are factors of -2 whose sum is 1.
2y^2+2y-y-1=0
2y(y+1)-(y+1)=0
(2y-1)(y+1)=0
y=1/2, y=-1
.
Set 1: (lower values)
  (smaller value)=-1
  (larger value)=-1

Set 2: (higher values)
  (smaller value)=1/2
  (larger value)=2
.
Ed