Answer:
Market Equilibrium is where : Market Demand = Market Supply . Any change in either of these changes the Equilibrium , Eqlbrm price & quantity.
Since , both the above shifts are linked to 'Change in Demand' , highlightig it undermentioned:
Demand : Quantity buyers are able & willing to buy , is affected by Factors - Price , Other Factors [Other Goods price , Income , Taste & preferences ] , Misclaneous (eg - seasonal factors) . Price makes change within the demand curve , other factors change (shift) the demand curve
a) Gasoline used to fuel vehicle combustion engines : faces more usage & demand in summers (seasonal factors) because of higher air conditioner use . This increase in demand (demand curve rightward shift) and excess demand creates competition among buyers & increases price .
b) Personal Computers : have been facing taste changes against them because of convenience associated with portable laptops . This leads to decrease in demand (demand curve leftward shift ) and excess supply creates competition among sellers & reduces price.