i need help in math.?any websites im so confuse but im not giving up!?

[ma]

"the sum or difference of two cubes"this small section is driving me nuts i cant move on... anyone have a good method or a simple way of manipulating the formula..

any websites or even your own method or anything that can help me ...my textbook explains it in a weird way that I can’t understand .


Just a problem in general Y^3-27
im not asking to for a solution but more of plan of developlement to help me solve this problem..

Ps this an example of my text book .. so i have the answer but if you have your own Preference please post the problem and explain.

Thanks peps