udbud og efterspørgsel micro økonomi

Hej jeg har været i gang med at løse opgave b) opg, kan se at j får det samme resultat som jeg skal men jeg tror ikke min fremgangsmåde er korrekt. har du mulighed for at tjekke det igennem. 

Demand:  P=40-Q
Supply:  P=10+1/2Q

a) Draw the demand and supply curves.

What is the market equilibrium price and quantity?
Market quilibrium is where the demand intersects with
The supply P=20 and Q=20

b) (dette er det korrekte resultat) A rise in consumer income causes the demand for bread to increase by 15 units at each price. Has equilibrium quantity risen as much as the rise in demand? Explain why or why not.
A rise in consumer income results in a right shift of the demand curve – horizontally by 15 units. The new equilibrium quantity is now set at Q=30 and price P=25, which is a smaller increase that the income increase caused. This is because of the fact that the supply curve is not perfectly elastic, so a shift in demand will change the price thus lowering the change in quantity.

b) (MIn udregning)

10 + 15 = 25

40-10 = 30