Find the sum of n terms of series (x+y) + (x^2+ xy +y^2)+(x^3...
We know sum of GP Sn=(a(r^n−1))/(r-1) when r>1 Where a= first term, n=nth term and r is common ratio Given sequence (x+y),(x^2+xy+y^2),(x^3+x^2y+xy^2+y^3),... to n terms. Multiplying and dividing each term by (x−y), we get