Find the sum of the GP : x(x + y) + x2(x2 + y2) + x3(x3 + y3) + …. To n terms

Answer : The given expression can be written as

= (x2+ xy) + (x4 + x2y2 ) + (x 6 + x3y3 ) + …. To n terms

= (x2 + x4 + x6 + … to n terms ) + ( xy + x2y2 + x3y3 + … to n terms )