The equation of the line fully simplified slope-intercept form.

Slope-intercept form is y = mx + c

Where m = slope,   c = y-intercept

First lets work out the slope.

If you look carefully, you'll see that for every one unit to the right, the line also drops one unit down. That means the slope is -1.

(it's negative because the line is going down diagonally)

The y intercept is where the line crosses the y axis.

If you look at the graph, you'll see that the line crosses at (0,3) , so the

y-intercept is 3

Now just substitute in the values for m (the slope) and c (the y intercept)

in the following equation:

y = mx + c      (put in the values for m and c)

y = -1x + 3      (-1x can also be written as -x)

y = -x + 3

y = -x + 3