Take any two points and plug them into the slope formula, let's take (1, -2) and (2, -6):
m = y2-y1/x2-x1
m = -6+2/2-1
m = -4/1
m = -4
Now we can plug this and one of the points into point-slope form:
y - y1 = m(x - x1)
Where y1 is the y-value of the point, x1 is the x-value of the point, and m is the slope.
y + 2 = -4(x - 1)
Distribute -4 into the parenthesis:
y + 2 = -4x + 4
Subtract 2 to both sides:
y = -4x + 2
