Please help me to solve this model..

To say that is equivalent to saying

So you just need to find the p that satisfies

Tip: This quadratic will give you two solutions for p, but you'll quickly see that only one makes sense in the problem, since we don't normally deal with negative prices and negative quantities in our universe :-)

After finding the equilibrium price, plug it back in to either of the demand equations to find equilibrium d.

Sorry, here's the cleaned up version...



I haven't had my coffee yet.