Question 457174
Passing through (4, 2) and perpendicular to the line whose equation is y = 8x + 9.
.
slope of:
y = 8x + 9
is 8
.
a line perpendicular must have a negative reciprocal slope:
-1/8
.
plug point and slope into point-slope form:
y - y1 = m(x - x1)
y - 2 = (-1/8)(x - 4)
y - 2 = (-1/8)x + 4/8
y - 2 = (-1/8)x + 1/2
y = (-1/8)x + 1/2 + 2
y = (-1/8)x + 1/2 + 4/2
y = (-1/8)x + 5/2  (this is what they're looking for)