Hi guys! first post here and i have been trying to figure this one out for quite some time no and i really cant seem to crack it no matter where i look at it, which is why i turn to you guys, the only people who can help me. Actually i just dont follow the sequence as the answer was already shown, i just dont understand the transition:
= x^3 + y^3 + x^2y + xy^2
= (x+y)^3 - 3xy(x+y) + xy(x+y)
I really need you guys' help to understand this one, ive been at this for at least a good hour and still no luck. please help!
I mean, when you moved to the other side of the equation, should they become negative? and where did come from?
I can barely make out of the second line either, but im assuming that once i understand that first line in your post i would be able to work my way to ur second line.
Again, sorry for troubling you, and thank you for the time and effort, very much appreciated.
For further info read here. 4. The Sum and Difference of Cubes