Question

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

Answer 1

x(x^3-y^3) + 3xy(x - y) 
x(x-y)(x^2+xy+y^2)+3xy(x-y) 
=x(x-y)(x^2+xy+y^2+3y)

Answer 2

Sir how did you remove the 'x' from the term 3xy

You wrote 3xy as 3y in next step

How did you do that