Find the slope of the line passes through (1,4) and (9,1)

-0.375

Step-by-step explanation:

Way one(the harder one):

Let the line which passes through (1,4) and (9,1) be f(x)=kx+b

Sub (1,4) and (9,1) in and we get

=> (9k+b)-(k+b)=1-4

                   8k=-3

                     k=-3/8 or -0.375

Therefore the slope of the line is -3/8 or -0.375

Way two(the easier one):

k= = = -

step-by-step explanation:

points a and b are equidistant from the desired line, so the line you find by using them will go through point r.

using points other than a and b will give the desired line only if they are equidistant from r. if they are randomly located, the perpendicular line you create will not necessarily go through point r, hence will not be a solution to the problem.