Question 980006
HI there,
a) Gradient = y2 - y1/x2 - x1 
Using (6,-4) and (-18,8)
 Gradient = 8 - (-4)/-18 - 6
 Gradient = 8 + 4/-24
Gradient = 12/-24 = -1/2
Using equation of the line
y - b = m(x - a)  and (6, -4)
y -(-4) = -1/2 (x - 6)
y + 4 = -1/2x + 3
y = -1/2x + 3 - 4
y = -1/2x - 1
or
2y = -x - 1
.........
b)A line that is perpendicular to 
another line have gradients that
multiply together to give -1
m1 x m2 = -1
-1/2 x m2 = -1
m2 = 2
Gradient of line perpendicular
to the first line has a gradient = 2
...........
c) Distance formula
Sqrt (x2 - x1)^2 + (y2 - y1)^2
A (6, -14) B (-18, 8)
sqrt (-18 - 6)^2 + (8 - (-14)^2
sqrt(-24)^2 + (22)^2
sqrt 1060
= 32.6 units
Hope this helps:-)