Find what the following equations become when the origin is shifted to the point (1,1): `x y-x-y+1=0`

Explanation

`(X+1)(Y+1)−(X+1)−(Y+1)+1=0`

`XY+X+Y−X−1−Y−1+1=0`

`XY−1=0`

`XY−1=0`, is the required equation.