Here are the solutions to the problems:
1. Using factorization by grouping, simplify r−k+1r2−k2+r+k
Step 1: Factorize the numerator.
The numerator is r2−k2+r+k.
We can group the terms as (r2−k2)+(r+k).
The term (r2−k2) is a difference of squares, which factors as (r−k)(r+k).
So, the numerator becomes (r−k)(r+k)+(r+k).
Now, factor out the common term (r+k):
Numerator $= (r+k)((