Expert: Abe Mantell - 1/26/2005

Question
Hi! Ok i have this really big math test tomorrow and i really need your help and fast! Please! Ok i need to know how to take a whole number and turn it into a fraction so i can multiply the two.  For example in the problem (-2,4) (-6,5), i can get the slope but then i dont get it.  Plese help!
                                       Rebecca


Answer
Hello Rebecca,

I am not sure what you mean by "...take a whole number and turn it into a fraction so i can multiply the two."  But,
to find the slope between 2 points, say (x1,y1) and (x2,y2)
you calculate:
(change in y)/(change in x)
=(y2-y1)/(x2-x1) OR (y1-y2)/(x1-x2), I will use the first
=(5-4)/(-6-(-2))
=1/(-6+2)
=1/(-4)
=-1/4

So the slope is -1/4...which means, for every
4 units one moves in the positive x-direction(to the right)
we need to go down (because of the "-") in the y-direction.

Or you can write it as 1/(-4), which would mean for
every 4 units we move in the negative x-direction (to the left),
we need to go up one unit in the y-direction.

Does this answer your question?

TTYL, Abe