A negative price Elasticity means that their is an inverse realationship betwen the price change and quantity demanded and therefore,Price decrease by 7% will increase the quanity demanded by 21%.
Price increase by 8% will decrease quantity demanded by 40%.This is because good x and y are complentary goods.They are complentary goods because they have a negative cross elasticity.
A positive price elasticity means that
there is positive realationship betwen the quantity demanded and price charged.Advertising decrease by 12%
Increasing income by 3% decrases the quantity demanded by 6% because the income elasticity is negative.