14 Algebra. 



29. The last three theorems have such a variety of applications 



that it is important that they should be committed to memory. 



We suggest the following scheme for keeping them in mind : 



x—a divides the difference of like powers. 



,. .' ^, *) difF(£T(?nc6' of like <?V(?n powers, 

 jr-f^ divides the -. _,., ,, ^ 



( sum oi like odd powers. 



The two cases which x-\-a divides can be kept distinct from 

 one another by noticing that the words difference and evert, which 

 go together, are the words which contain the ^'s. 



