Question 1058333
Hi there,
Find the gradient (Slope) of Main Street using the
coordinates that it intersects.
(-2, 17) and (-22, 33)
Gradient (Slope) = y2 - y1/x2 - x1
Gradient(Slope)  = 33 - 17/-22 -(-2)
Gradient (Slope) = 33 - 17/-22 + 2
Gradient (Slope) = 16/-20 = -4/5
Lines that are perpendicular to one
another have gradients (slopes) that 
multiply together to give -1
m1 x m2 = -1
-4/5 x m2 = -1
m2 = 5/4
Using the straight line equation:
y - b = m(x - a)
where m = 5/4 and (a,b) = (80, 9)
y - b = m(x - a)
y - 9 = 5/4(x - 80)
y - 9 = 5/4x - 100
y = 5/4x - 100 + 9
y = 5/4x - 91
This is the equation of Grimes
Boulevard in slope - intercept form.
Hope this helps :-)