WEBVTT
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all right. Fun stuff here with the solving quadratic
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equations. By completing the square, you're getting a
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little bit more advanced, a little bit more difficult
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. If I wasn't being told to solve this with
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completing the square, it probably used the quadratic formula
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. But here we go. So let's start by
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isolating the X squared term and the ex term,
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Um, by subtracting four from both sides, that's
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the first thing we gotta D'oh. Then I'm gonna
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divide everything by two to get the, um,
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lead coefficient to be one. Then I can actually
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do what it's called quote unquote completing the square.
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So what do I add to this left side?
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To make it a perfect square, try no meal
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. You take half of the B value half of
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seven houses, seven force and then you square it
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. 74 squared is 49 over 16 seven scores 49
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4 square to 16. So we're going to add
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49 16th to both side. That's called completing the
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Square. Um, I am gonna change negative to
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two negative. 32 16th. That's just getting myself
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a common denominator, because I'm gonna have to add
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those anyway, so Why don't we add 49 16
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support side? Why did we take half of this
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? Be value and square it and and the left
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side so we could make it a perfect square trey
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. No meal that can be factored easily as this
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. It would be X squared on that X squared
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, but acts plus seven hats, seven forced squared
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. So that's the factory ization of this. All
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right, on the right, we simplify, and
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we get 17 16th. Then we can take thes
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square root herbal sides. Um, and we get
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X plus seven. Force equals plus or minus the
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swirl of 17 over for. So the square to
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17 is the square to 17. Scored. 16
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is four. We're just one step away from heaviness
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. All factor is gonna give myself a little bit
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more room here. I have an assault, brother
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, and that is to subtract seven force from both
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sides. Negative seven. Force closer Money. Nous
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the square root of 17 over four. That is
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our solution. It is not rational, but and
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it's ugly, but it's our answer number less negative
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seven force plus or minus two squared of 17 force