Question

What happens to the value obtained for the slope if the coordinates of the two ordered pairs aren't subtracted in the same order? Can you give an example?

Answer 1

e.g.
A(4,6)
B(9,-1)

slope AB = (-1-6)/(9-4) = -7/5 or -(7/5)
slope BA = (6+1)/(4-9) = 7/-9 or -(7/9)

notice that as long as I am consistent in the order that I subtract, I do get the correct answer.

Of course, by definition, slope = the y's / the x's , that obviously has to stay the same.

Answer 2

so by lining ab and ba up you take the #'s (1&6) to use them together?

Answer 3

the numerator of the slope value is always the difference of the y values, the denominator is always the difference of the x values.
The important thing is that you subtract in the same direction.
That is, if you take the first y - the second y, then you have to take the first x - the second x, and vice versa.