5 3/4 divided by 4 1/2 23/4 divided by 9/2 23/4 times 2/9 46/36 = 1 and 10/36 (reduced) = 1 and 5/18 inches
A line parallel to your equation has the same slope, so it should be in the form:
y = (-3/2)x + b
To figure what "b" has to be, plug in the point (4,0) and solve:
0 = (-3/2)*4 + b
0 = -6 + b
6 = b
So the equation of the line is:
y = (-3/2)x + 6
I think its 1/10 miles/hour