Question 27182
Use the formulas
{{{(y[2] - y[1]) / (x[2] - x[1]) = slope}}}
and
{{{(y - y[1]) / (x - x[1]) = slope}}}
first
-2 - (-2) / -4 - 2 = 0
then
y - (-2) / x - 2 = 0  (I now know the slope is zero)
y + 2 / x - 2 = 0
y + 2 = 0
y = -2
That makes sense, because y didn't change (2, -2) (-4, -2)
so, (any x, -2) solves the equation.