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Alright, what I'd like to do is show you how to find the equation of a line when I, given
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the slope of 4, which goes to the point 6,9.
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So first thing I'm going to do is, just to remember, we can write an equation that's
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two different forms.
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We can write it as y equals mx plus b, which is called slope intercept form.
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And we can also write as y2 minus y1 equals m times x2 minus x1, which we call the point
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slope form.
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So either way you want to use it is perfectly fine.
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For this example, I'm going to show you how to find it in using the point slope form.
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So what we have is we have a slope is 4.
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So therefore on this video, I'm going to show you the other way else, you have to do it
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in y because I'm not supposed to be a form.
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So this form, what I'm going to do is, I know that slope is 4, so that's going to equal
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my m.
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And then what I also have is I have an x and a y coordinate.
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Now on this problem, you can see it's a little more difficult because what we have is, we
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have two x's and we have two y's.
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So which one am I going to play it into?
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Well, it doesn't really matter which one you're going to play, which one you want to
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plug it into.
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But preferably what I like to do is, I like to label this x1 and y1 and therefore I can
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erase my x2 and my y2.
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And I'm going to leave my x1 and my x1 and I'm going to leave my x and y open so they're
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going to be a part of my equation.
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And now what I'm going to do is I'm going to plug in my m and my 2 points.
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So therefore I have y minus 9 equals m times, sorry, m is 4.
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Slope is 4 times x and then minus my x, which is 6.
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Then what I can do is, use a distributed property.
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And then I can just add this over.
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And it has 15, right?
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That's 50.
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So that's how you find the slope of a line that goes through the point.
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6, 9, it has a slope of 4.
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So that's how you find the slope of a line that goes through the point.
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And now what I can do is, I'm going to put this over.
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And then I can just add this over.
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And then I can just add this over.