Question 846676
The easiest way to group 9c + xc + 9w^2 + xw^2 is by finding terms that have something in common.  As you can see, 9c + xc have c in common and 9w^2 + xw^2 have w^2 in common, so we can group the first two terms together and the last two terms together and factor out the common terms from each:


In 9c + xc, we can factor out the c, giving us:   c(9 + x)


In 9w^2 + xw^2, we can factor out the w^2, giving us:  w^2(9 + x)


Combining these together gives us:


c(9 + x) + w^2(9 + x)


We can see that both expressions on each side of the + sign have the term (9 + x) in common.  So, we can factor that out of our combined expression above:


(9 + x)(c + w^2), which is our final answer.