Question

How do you factorise with letters?
e.g : 4p + pq + 5pr

Answer 1

4p + pq + 5pr
All of them have p as a common

So, we just take p out to factorize

p(4 + q + 5r)

Answer 2

As you can see, p is present in each term. You may factor that out. You want to factor out the most common factor that is seen in each term.
p (4 + q + 5r)