Could someone explain in more details this simplification?
I hope you know the formula: (*).
For the first fraction, the numerator is , using (*) it becomes: . (I used the rule )
For the second fraction, the numerator is , which can also be written: (I used the rule ). Using (*) again, we obtain .
So we have:
(I rearranged the factors, I hope this helped).
Now, if we want we can apply (*) again for :
(I used the rule ).