Use the given points to find the slope of the line.
Example Solution: y-1=-3/4(x-1)
Practice makes perfect
Let's start by recalling the general form of an equation in point-slope form.
y-y_1=m(x-x_1)
Here, m is the slope and (x_1,y_1) is a point on the line. To write the equation for the line given by the graph, we must find the slope and one point.
From the graph we can see that two points on the line are (- 3, 4) and (1,1). To find the slope of the line, we can determine the vertical change, rise, and horizontal change, run, between these points.
We can see that, from (- 3, 4) to (1,1), we move down3 units and right4 units.
rise/run = -3/4 ⇔ m= - 3/4
We can now write the equation in point-slope form. We will substitute the slope m=- 34 and either one of the points into the equation. We will arbitrarily choose the point ( 1, 1).
y- 1= -3/4(x- 1)
