Question

Factor completely: 5ab + 3ay + 5b + 3y

Answer 1

Notice how two terms have both 5 and b in them. What can we do about that?

Answer 2

Welcome to OpenStudy!
This expression can be factored by grouping.
To help you get started:

Re-write the first two terms as a(5b+3y). Rewrite the last two terms as (?)(5b+3y), where (?) is a simple constant.

What term seems to be common to both the first two terms and the last two terms of the original expression?