00:02
Or as to write the equation of the line that contains these two points, the points 7 comma 2, and the point 4, comma, 4.
00:14
All right, so we have a couple of different equations of a line that we should know.
00:17
We should know y equals mx plus b.
00:20
That's the slope intercept form.
00:22
I can find the slope given these two points, but i don't know the y intercept right off the bat.
00:27
We should know also point slope form of a line.
00:32
And that's probably the one that i'm going to use here because for point slope form of a line, i need a point and the slope.
00:38
And i've got two points.
00:39
I can pick either of them to use.
00:41
And then i can find the slope.
00:43
So let's talk about that.
00:45
The slope formula, m, is equal to.
00:48
And that is y2 minus y1 over x2 minus x1.
00:54
That is the change in y values over the change in x values.
00:59
So, you know, maybe we'd consider this guy x1.
01:02
And this one would then be x2y 2.
01:06
So when i substitute in my y value 4 minus my y value there would be 2 over my x value 4 again minus 7.
01:18
So 4 minus 2 is 2, 4 minus 7 is negative 3.
01:23
So my slope would be negative 2 thirds.
01:28
All right.
01:28
Now point slope form of a line.
01:31
That is the form where it looks like...