Name: 保理表達式的面積模型 (Area models for factoring expressions)
Uploaded: 2021-01-14T10:13:47.000Z
Duration: 3 min 5 s
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- [Instructor] Averil was trying to factor

過去簡單式

形容詞最高級

She found that the greatest common factor

of these terms was six and made an area model.

What is the width of Averil's area model?

So pause this video and see if you can figure that out,

and then we'll work through this together.

All right, so there's a couple of ways to think about it.

and she figured out that the greatest common factor was six.

this could be rewritten as six times something else.

maybe I could write width right over here,

So imagine that the area of this rectangle

Now, what's interesting is is that they broke up

And, of course, these aren't drawn to scale,

'cause we don't even know how wide each of these are

but it's to show that we can break our bigger area

And what's useful about this is we could think about

So what is the width of this pink section right over here?

Well, six times x squared is six x squared,

So let's see, if I take six times negative three,

then I have to multiply it times an x as well

So six times negative three x is negative 18x.

So we figured out the widths of each of these subregions,

The total width is going to be our x squared

And you could substitute that back in for this,

and you could see, if you multiplied six times

you would indeed get six x squared minus 18x plus 12.