First we want the slope.
slope = (y2 - y1) / (x2 - x1)
slope = (29 - -11) / (-7 - 3)
slope = (29 + 11) / (-10)
slope = (40) / (-10)
slope = -4
.
Now we want point-slope form:
y - y1 = m(x - x1)
y - 29 = -4(x - -7)
y - 29 = -4(x + 7)
y - 29 = -4x - 28
y = -4x - 28 + 29
y = -4x + 1
that's slope intercept form