 This video will talk about factoring four terms. So when we have four terms, we're going to factor that by taking the first two terms, d cubed plus 6x squared, and then we're going to take the second two terms and see what we can have in common there. So we're trying to find the greatest common factor of each one. So for the first two terms, they have a three in common, and the exponent, the smallest exponent would be 2, so 3c squared is the common factor. I have 3c squared, and I need one more factor of c to make that first term correct. And now I need 3 times 2, a positive 2, to give me 6, and I have c squared on the outside, and that's all the c's that I need, so I would be done factoring that one. And then in the next set, c plus 2, it may not look like it has anything in common, but they do, they have a positive 1 in common, if nothing else. So it's plus 1, and then 1 times c would be c, and 1 times 2 would be 2. Now we've factored the first two and the last two terms, but you'll notice that we still have two terms. We're not factored yet. When you see this plus in the middle of your terms, you still have terms, you're not factored. So I have to find the greatest common factor again, and I'm going to find the greatest common factor of each term. And if we did it right, that should become real obvious that it's going to be this thing in the parentheses. If we factored the first part right, these two should match. So my greatest common factor is c plus 2, and just like we were doing before, now I need this 3c squared to go with the c plus 2, and I need this positive 1, because I already have the c plus 2, but I need that positive 1, and now I am completely factored. One more try. We have 7x squared plus 21x, that's my first two terms, and then I've got 6x plus 18, and that's my second two terms. These first two terms, 7 and 21, look like they have 7 in common, and I have an x squared and an x, so they both have an x factor, so I can take the smallest exponent, which is just plain x. Here's 7x, I need one more factor of x inside to give me when I distribute 7x squared, and 7 times 3 will give me 21, and I already have the x on the outside, so I just have x plus 3 as my other factor. Now I'm looking at my second two terms, and I want to write my sign when I write my common factor. 6x and 18 have a positive 6 in common, and then I need a factor of x to give me 6x when I distribute, and 6 times 3 would be 18. And remember we said that we wanted these two parentheses to match if we had factored correctly, and we did. So we're ready to do this two term greatest common factor, and in here that parentheses, like I thought I had done, is my greatest common factor. And then the other factor, I've got the x plus 3, so I need the 7x, and I got the x plus 3 in this term, but I still need the plus 6. And x plus 3, 7x plus 6 would be my greatest, or would be my factored form, completely factored form.