Question 68754
(X+Y)3rd power=(X+Y)(X+Y)(X+Y)
=(X+Y) (X 2nd power +2XY +Y 2nd power)
what do you want?
(x+y)^2=(x^+2xy+y^2)
hence (x+y)^3=(x+y)(x^2+2xy+y^2)
(x+y)^3=x^3+3x^2y+3xy^2+y^3