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Let say that you started off with three apples

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and then I were to give you another seven apples.

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So my question to you,

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and this might be very obvious

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is how many apples do you now have?

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and l'll give you a second to think about that

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Well, this is fairly basic:

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you add 3 apples,

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now I'm going to give you 7 more

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you now have 3 plus 7

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you now have 10 apples.

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But let say I wanna do the same type of thinking

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but I'm too lazy to write the word apples

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Let say that instead of writing the word "apples",

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I just use the letter "a".

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and I say... let say...

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and this is, say, a different scenario...

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you start off with 4 apples

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and to that I add another 2 apples.

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How many apples do you now have?

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And instead of writing "apples",

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I'm just going to write "a's" here.

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So, how many of these "a's" do you now have?

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And once again,

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I'll to give you a few seconds to think about that.

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Well, this also might be a little bit of common sense for you

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if you had four of these apples,

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whatever these a's represented,

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if you have 4 of them and then you add 2 more of them

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you're now going to have 6 of these apples.

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But once again,

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we started off assuming that "a's" represent apples

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but they could have represented anything

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If you have 4 of whatever "a" represents

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and then you have another 2 of whatever "a" represents,

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you'll now have 6 of whatever "a" represents.

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Or if you just think of it as if I have 4 "a's"

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and then I add another 2 "a's",

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I'm going to have 6 "a's".

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You can think of 4 "a's" as a + a + a + a.

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And if to that I add another 2 "a's".

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So + a + a. That's 2 "a's" right over there.

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How many a's do I now have?

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Well that's 1, 2, 3, 4, 5, 6.

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I now have 6 "a's".

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So thinking of it that way, let's get a little bit more abstract.

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Let say that I have 5 "x's", whatever "x" represents.

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"x" could be some number...

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So I have 5 of whatever that number is

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and from that I subtract 2 of whatever that number is.

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What would this evaluate to?

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How many of these "x's" will I now have.

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So it's essentially "5x - 2x" is going to be what times "x".

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And once again, I'll give you a few seconds to think about it.

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Well, if I have 5 of something

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and I subtract 2 of those away,

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I'm going to have 3 of that something left.

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So this is going to be equal to 3x.

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5x - 2x is equal to 3x.

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And if you really think about what that means.

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5 "x's" are just: x + x + x + x + x.

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And then we're going to take away 2 of those "x's".

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We're going to take away 2 "x's".

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So take away one "x", take away 2 "x's".

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You are left... you are going to be left with 3 "x's".