课程: Test Prep: GRE

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Algebraic identities

Algebraic identities

课程: Test Prep: GRE

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Algebraic identities

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- [Voiceover] So certain, what we call quadratic identities or algebraic identities are useful to know for the GRE. So what I mean by that is just kind of recognizing what things turn into. So let's start with x plus y squared. Well if we FOIL'd that or if we multiplied it by each other we would get x plus y times x plus y and we would get x squared plus xy plus xy plus y squared which simplifies to x squared plus two xy plus y squared. Now the thing about this in terms of being an identity, I want you to recognize that when you have something that looks like this in a problem that you may see this as well and vice versa. It's kind of a visual thing, you wanna be familiar with these identities because they're somewhat common in math. So let me show you another one here. Let's see if, what happens if we do x minus y squared. Well, that's gonna be x minus y times x minus y. That's gonna simplify to x squared minus xy minus another xy plus y squared and that will simplify to x squared…

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