00:02
All right, so we're talking about linear equations here.
00:06
So if you recall the slope intercept form of a linear equation is y equals mx plus b, where n is your slope and b is your y intercept.
00:27
So if we have this question where we have to find the equation of the line or the linear equation of the line, function that passes through these two points, 3 comma 5 and 0 .17.
00:44
We want to first find the slope between these two points.
00:49
So to find the slope between these two points, we'll bring this back up later, the slope intercept equation.
01:01
Let's label these two points as such.
01:07
X sub -script 1, x sub 1, y sub 1, will be the point 3, 5, and x sub 2, is 0, y sub 2 is 17 for the second point.
01:21
So for the slope, rise over run, or y sub 2 minus y sub 1 over x sub 2 minus x sub 1.
01:37
Remember this is m equals that slope formula.
01:42
So if you just substitute the given values into the slope formula, right, we have 17 minus 5 over x sub 2 minus x sub 1, would be 0 minus 3.
02:00
Then you have 12 over negative 3, which gives us a simplified slope of m equals negative 4.
02:13
So if we go back to the slope intercept equation, which is y equals mx plus b.
02:25
Let's go over to another whiteboard here.
02:37
So we have y equals mx plus b.
02:39
We just found that the slope is negative 4.
02:49
So we'll put that on the side.
02:55
Let's use one of the original two points.
02:59
So how about we use 0 comma 17, that second point? 0 comma 17.
03:05
And when we use that point, what we mean is we're going to substitute the coordinates of that point, x and y, into the slope intercept equation on the left...