Question

prove that
(x+y)^3= x^3 + y^3 + 3xy (x+y)​

Answer 1

answer : (x+y)^3 = (x+y)^2 (x+y)

= (x^2+y^2+2xy) (x+y)

= x^3+xy^2+2x^2y+x^2y+y^3+2xy^2

= x^3+y^3+3x^2y+3xy^2

= x^3+y^3+3xy(x+y)

hence proved