Knowing how to double factor in math will come in handy in a wide variety of different situations. Learn about double factoring in math with help from an experienced mathematics educator in this free video clip.

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Knowing how to double factor in math will come in handy in a wide variety of different situations. Learn about double factoring in math with help from an experienced mathematics educator in this free video clip.

Part of the Video Series: Elementary Math

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Hi my name is Marija. I'm a mathematician and today I'm going to show you how to do double factoring in math. So if you have problem like 2x squared plus 14x plus 20 and you're asked to factor it, the first thing you might notice is that this is a quadratic but you might also notice that A is not 1 and you might notice that you can also take a GCF out of this quadratic, this trinomial. So if you look at all three terms 2x squared, 14x and 20, you see that you can take out a 2, a 2 is the GCF. So we're going to go ahead and factor out a 2 to begin with. When I do that I'm left with X squared plus 7x plus 10 so that was your first step in factoring. You factored out the GCF 2 but now you see that inside the parentheses you still have a quadratic and you know that if you have a quadratic you can try to factor it with product and sum. The product is 10 and my sum is 7. So if I start to think of two numbers that will multiply to give me 10 and add to give me 7 I know that these two numbers are 5 and 2 so I can factor this quadratic further. I have to keep the 2, so don't forget that if you are double factoring, always keep the GCF that you first factored out. Now inside though I'm going to split this into two parentheses and because the two numbers I chose were 5 and 2 I'm going to write X plus 5 multiplied by X plus 2. So now the quadratic was factored into this, 2 was my initial GCF and this is the complete factorization after double factoring my original expression. My name is Marija and I just showed you how to do double factoring in math.