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We're asked to find the[br]square root of 100.

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Let me write this down bigger.

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So the square root is this[br]big check-looking thing.

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The square root of 100.

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When you see it like this,[br]this means the

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positive square root.

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If you're familiar with negative[br]numbers, you know

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that there's also a negative[br]square root, but when you just

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see this symbol, that means[br]the positive square root.

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So let's think about what[br]this is saying.

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This is asking us find the[br]number, the positive number,

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that when I multiply that number[br]by itself, I get 100.

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So what number when I multiply[br]it by itself do I get 100?

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Well, let's see, if I multiply[br]9 by itself, that's

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only going to be 81.

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If I multiply 10 by itself,[br]that is 100.

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So this is equal to-- and let[br]me write it this way.

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Normally, you could[br]skip this step.

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But you could write this as[br]the square root of-- and

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instead of 100, 100 is the same[br]thing as 10 times 10.

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And then you know, the square[br]root of something times

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itself, that's just going[br]to be that something.

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This is just equal to 10.

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So the square root[br]of 100 is 10.

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Or another way you could write,[br]I guess, this same

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truth is that 10 squared, which[br]is equal to 10 times 10,

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is equal to 100.

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