Slope-intercept form is y = mx + b, where m is the slope and b is the y-intercept. To find b, you first need to calculate slope and see where the line intersects the y-axis.
To get m (slope), use the form y1 - y2/x1 - x2. It would look like this:
2 - 12/-1 - 4. This simplifies to:
-10/-5, which further simplifies to 2. Now, graph the points to find y....
My graph shows that the line intersects at (0, 4), so slope-intercept form would look like:
y = 2x + 4 (remember, 2 is the slope and 4 is the y-intercept)
Hope this helps.