# Factorise using Double Common Factors

## Transcript

What I’m gonna do whenever you have four terms, I’m gonna try to group them into twos okay? So I just put like in just think those brackets are invisible. I’m just going to put brackets in there, so I’m going to do factorize this by individually and this individually. So I’m going to have two factorizations going on, so here guys what’s the common factor? a, a is common, so

I’m going to take a out and we’ll have x plus y leftover plus see here b is a common factor, so I took b out and we have x plus y left over. Now we’ve left with this term and this term. See how x plus y is common, that’s a common factor so I’m going to take x plus y out and would so you can take it out in the front or you can take it out the back whatever you like doesn’t really matter and we have a plus b left over so a plus b times x plus y. I’ll try these two together this one and that one so here what’s common guys?

See how we have a three and we have a six? What’s common with three and six? What’s the common factor of three and six? It’s three, isn’t it? Three and we also have a is common a is common, so I’m going to take out 3a here so if I take 3a here. We’ll just have x left over here and we’ll have because 6 divided by 3 is 2. I’ll have 2 y leftover and here guys I actually put the answer there already but b is common to see how b is common, so I took b out I’m going to take negative b out because I don’t want the negative there so take negative b out so here I’ll just have x leftover and here I’ll have 2 y leftover but see how this sign is a positive I changed it to a negative why do you think I did that?

Because negative negative will eventually when I expand it out to make a positive. That’s a little trick there you have to remember this is where everyone makes mistakes guys okay so be extra cautious, so now we’ve got this term and this term. What’s common between those two terms? x minus 2y is common? It’s exactly the same, so I’ll take that out as a common factor, so you can take it out at the back, you can take it out of the front whatever you like doesn’t really matter it’s the same thing.

So we just have 3a left here and minus b left here, so that is the answer. So you can have x minus two y times 3 minus b you can swap these around as I said doesn’t matter it’s the same. 