If |x| < 1, |y| < 1 and x $\neq$ y, then the sum to infinity of the following series (x + y) + (x^{2} + xy + y^{2}) + (x^{3} + x^{2}y + xy^{2} + y^{3}) + ..... is :

(1) $x+y+xy\over(1-x)(1-y)$

(2) $x+y-xy\over(1-x)(1-y)$

(3) $x+y-xy\over(1-x)(1+y)$

(4) $x+y+xy\over(1+x)(1+y)$