First, spot 2 coordinates that are found on the line. Let’s take (0,5) and (-2,13).
To find the slope use formula: (y2-y1)/(x2-x1). We get : (13-5)/(-2-0) = 8/-2 = -4
For equation of line we know y=mx+b where m is the slope and b is the y-intercept. We know m=-4. So we have:
y = -4x+b
To find b, we just replace one of the coordinates for x and y. Let’s take (0,5)
5 = -4(0)+b
b=5
So the equation of the line is:
y = -4x+5