Let's look at the given equation to first identify the constant of variation. Then we can look at the marked points to calculate the slope.
Constant of Variation
To find the constant of variation of an equation, we need to remember that it is the rate of change of a direct variation. The general form of a direct variation equation sets the dependent variable y equal to the rate of change multiplied by the independent variable x.
y= mx ⇔ y=change in y/change in x* x
Let's look at the given equation to identify this value.
y= - 4/5x
The constant of variation is m=- 45.
Slope of the Line
To find the slope, we will substitute the points shown in the graph into the Slope Formula.
m = y_2-y_1/x_2-x_1
In this case, the given points are (0,0) and (- 5,4). Note that when calculating slope, it does not matter which point you choose to use as (x_1,y_1) or (x_2,y_2).
