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Course: Measurement & Data - Statistics & Probability 189-200>Unit 1

Lesson 5: Area and the distributive property

Area and the distributive property

Sal uses the distributive property to find area of rectangles. Created by Sal Khan.

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• why do they call it distributive property?
• Because the term outside the parentheses is distributed to all the terms inside the parentheses. Distribute is another way to saying share with.
• At it says the numbers are equivalent ,how is that?
• As I understand, it means that both formulas will give you the same number; so it doesn't matter how you go about finding the area, either with formula a or b, both will provide the same result and therefore are equivalent.
• . (make this famous for no reason)
• ok I will try
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• because the formula for finding Area is: Area = width*height or Area = height*width, there is no difference in using either you will still get the same answer if you plug in the correct value.

so your conclusion is that why are we adding and multiplying, well, the formula says so. and that's why Sal multiplied, but, you might be wondering why we added. This is because we had to find the width of the object shown in the video, if we had used 8 or 12 instead, we would have only found a particular portion of the whole thing instead of finding the whole area of the whole object.

so Sal added 12 and 8 to find the total width of the object and then plug the values in and this is what it looks like:

Area = height*width
so: Area = 9*12+8(sums up to 20)
Area = 9*20 = 180(Whatever measurement unit)

That's how we can find why he added and multiplied.

Hope this Helped :)
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• why are we both adding and multiplying?
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• So, just to make sure I'm not being "tricked" here somehow... We are obliged to use the "distributive property" to make sure that the "order of operation" is being applied, right?! I mean, multiplication before addition, right? ^_^
• Not exactly. According to the order of operations (PEMDAS) you must evaluate the terms in the parentheses first. He was not saying that you must use the distributive property to calculate the area, just that this problem serves as an example of why the distributive property is true.

9(8+12) == 72+108 == 9(20) == 180

Since this is essentially a simple addition and multiplication problem, the Commutative Property dictates that the order in which the terms are evaluated will not affect the answer.
• If you feel like Sal is speaking to slow go to the settings button and click on playback speed and click on the speed right for you. Hope this helps!
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• can you make it BIGER
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• can we jest chat?
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• At , what are the two strategies?