SOLUTION: {{{(x^2-y^2)/(x^4-x^3)}}}÷{{{(x-y)/x^2}}}÷{{{(x^2+2xy+y^2)/(x+y)}}}

We take care of the ÷ 's first in order left to right. So we put
parentheses arould the first two fractions so that we do that
division first.

( ÷ ) ÷ 

Within the parentheses we invert the second fraction and change
the division symbol to a multiplication symbol

( · ) ÷ 

Now we invert the third fraction and change the division symbol
to a multiplication:

( · ) · 

Now we don't need the parentheses around the first two any more:

 ·  · 

Now we indicate the product of all the numerators over the
product of all the denominators:



Now we factor the  as ,
the  as , and
the  as 



We cancel the in the top with the  in the bottom.
There are two  factors in the top that cancel
with the two  factors in the bottom.
The  in the top cancels into the  in the bottom,
leaving only an  or just  in the bottom. So we have only 
this left after canceling:



Edwin