Question

Here's a graph of a linear function. Write the

equation that describes that function.
Express it in slope-intercept form.

Answer 1

y = -3x+4

Explanation:

Slope intercept form of a line is given by y = mx + b

Where

m is the slope

b is the y intercept.

To find m, we need to take any arbitrary 2 points and see how many units up/down and how many units right/left we need to go from one to another. Basically change in y by change in x.

Let's take 2 arbitrary points: (0,4) & (2,-2)

So we need to go -6 units from y = 4 to y = -2. We need to go 2 units from x = 0 to x = 2.

Hence slope is change in y by change in x, which is -6/2 = -3

b is the y-interceept, the place where it cuts the y axis. Looking at the graph, it is at y = 4

Now we can write the equation as :

y = -3x+4