Question

What are the factors of (r+t)(e)

Answer 1

Depending on the values of  'r',  't', and  'e', the numerical value of that expression
might have many factors. 

For example, if it happens that r=5, t=1, and e=4 for an instant, then, just
for a moment,  (r + t)(e) = (5+1)(4) = 24, and the factors of (r+t)(e) are
1,  2,  3,  4,  6,  8,  12, and  24 .   But that's only a temporary situation.

The only factors of (r+t)(e) that don't depend on the values of  'r',  't',  or  'e' ,
and are always good, are  (r + t)  and  (e) .