prices depend on total quantities as follows:

产品的价格由以下因素决定
where the slope of this line is -b.

这条图线的斜率是-b
Now, for those of you who took Economics 115 or equivalent,

我来问一下学过经济学115的同学
what is the name of this line I've just drawn?

这条曲线叫什么名字
That was way fewer responses than I wanted. Let's try again;

没几个人回答啊我再问一遍
what's the name of this downward sloping line that I've just drawn?

这条向下倾斜的曲线叫什么
It's a demand curve. Thank you; it's a demand curve. That was the demand.

它叫需求曲线感谢你的回答
It tells me the other way around

它直观的显示出
to look at how prices correspond to quantities,

价格如何与产量对应
it tells me the quantity demanded at any given price.

即在给定的价格上需求量是多少
We'll come back to that in a second.

我们一会再继续讨论这一点
Meanwhile, let's just finish up what we're doing here and put in payoffs.

我们先把收益写出来吧