Factorising Difference of Squares: Polynomial Terms and Common Factors

Transcript

Now! This one, we don’t really need to do much and this one, it’s so this one is x squared and this one is 2x minus 1 squared. They already did it for you. They already put it as two square numbers. It’s a square number minus a square number. So this is your a and this is your b, so remember we do a plus b, a minus b. So I’m going to say x minus 2x minus 1, x plus 2x minus 1, okay? I want you to keep these brackets here just for the sake of not making any silly mistakes with the signs. Do you get the idea? x minus 2x minus 1, x plus 2x minus 1, okay?

It’s a bit big but make sure you watch that out. Now, the reason why I told you to keep these brackets here is because when you expand this out, you get x minus 2x plus 1 because minus minus is plus, everyone forgets to do that don’t make that mistake guys, and here you don’t really need to worry about the signs. It’s going to be x plus 2x minus 1, okay? And then simplify it. x minus 2x is negative x plus 1 and x plus 2x is 3x minus 1.

Now, you can leave it like that guys but teachers like you to simplify and so it looks in its nicest form, but when we have a negative in front we don’t really like that. So if you want to make this look really nice and neat and you want to impress your teachers, swap these around. So I have 1 minus x, so just top those around, and then now we don’t have a negative from the in front of the first number, okay? So that’s the only thing I want you to do. Okay! 2m squared minus 32. Now remember guys what I said in the previous part, I told you that with all of these factorization questions, first of all, find the common factor.

We have a common factor here of 2, isn’t it? So factorize by 2 first because we have a common factor. And then we’ll have m squared minus 16 left. So now we’ll just concentrate of in this part. We know that 16 is 4 squared, so we’ve got a square number, minus the square number. So we have m and 4. So it’s m plus 4 m minus 4 with the 2 out the front, okay?