c.) Describe the exact numerical relationship between the change in PX and the subsequent change in QDx: as PX increases by $1, QDx increases/decreases by ____ units. Repeat for PB and its impact on QDx. Now look at your two answers and the original equation: what's the connection? Finally, merely looking at the equation, what is the impact of a $1 increase in PA on QDx? Of a $1 increase in Y on QDx?