At a Price Of $\$ 2.80$ Per Gallon, the Average Weekly Demand by Consumers for Gasoline

Short Answer

At a price of $\$ 2.80$ per gallon, the average weekly demand by consumers for gasoline is 43 gallons. If the price rises to $\$ 2.85$ , the weekly demand drops to 39 gallons. Assuming demand is linear, let $Q=b+m p$ , where $Q$ is the weekly quantity of gasoline demanded and $p$ is the price per gallon. Then $b=―――$ and $m=―――$