NO.PZ2023010401000001
问题如下：
A college student’s monthly demand for pizza is given by the equation:
The student’s current monthly food budget is $500, the price of a pizza is $5, and the price of a bottle of cola is $1.25/bottle. If the student’s monthly food budget were to increase to $700, the slope of her demand curve for pizza would be closest to:
选项：
A.-2.42. B.-1.43. C.-0.70.解释：
Solution: B.
斜率为什么不是-0.7呢，demand cureve 不是Q等于多少P 么？为什么是P在左边
