Your answer should be a polynomial in standard form.
(5 + w)(w + 4) = ?
to expand this polynomial, we should multiply the factors in order from left to right. hopefully you can follow this process -
5w + 5*4 + w^2 + 4w.
to simplify, we combine the like terms, to get:
w^2 + 9w + 20
hope this helped! sorry if this wasn't too clear.
here are a few websites that may help you understand this better:
also try out Symbolab's expansion calculator. it provides a step-by-step expansion of polynomial expressions as well.
if you have some time, give these a try! Google searches are also useful to help you learn more too!