tolong penyelesaiannnya ya sama caranya

2y/(x + 1) - x/(y - 1) = 1 |.2| 4y/(x + 1) - 2x/(y - 1) = 2
............................................. -3y/(x + 1) + 2x/(y - 1) = -1
---------------------------------------------------------------------- +
.............................................. y/(x + 1) = 1 => y = x + 1

(xy - x + y - 1)/(2xy)
= (x(x + 1) - x + (x + 1) - 1) / 2x(x + 1)
= x(x + 1) / 2x(x + 1)
= 1/2