SOLUTION: Factor completely by grouping: {{{2y + mx^3 + my + 2x^3}}}

 
Since we cannot factor the first two terms or the last
two terms, we try reversing the two middle terms:



Now we can factor the first two terms AND the last two terms:

We factor  out of the first two terms and factor  
out of the last two terms:



Notice that  is the same thing as 

So we replace the  by 



Now we have a common factor of 

So we factor  out



Edwin