price-supply and price-demand equations?

[sandellie4]

I have a problem like this. At $2 per bushel, the annual supply for soybeans in the South is 9 billion bushels, and the annual demand is 6 billion bushels. When the price FALLS to $1.50 per bushel, the annual supply DECREASES to 8 billion bushels, and the annual demand increases to 7.4 billion bushels.

So, I have:

(9, 2)
(8, 1.50)

What I don't understand is whether or not I need to use NEGATIVES for these points because of the decreases??? when I use the points to find equations.

Sandy

[stapel_eliz]

No; the "falls" just confirms that, yes, the second values are lower than the initial values.