Answer
In supply function q = 90 ,
p= 130 in demand function,
$65, is the equilibrium price
90 is the equilibrium quantity
The market equilibrium point (q,p);
(90,65)
Explanation
Supply function
2p-q-30=0
Demand function
(p+10)(q+30)=8400
Solve for supply function q,
q = 2p-30 -> eq.1
Substitute eq.1 to demand function;
(p+10)(2p-30+30)=8400
(p+10)(2p)=8400
2p2+20p-8400=0 ;divide by 2 to simplify
p2+10p-4200=0; find the roots by completing the square
In supply function q = 90 ,
p= 130 in demand function,
$65, is the equilibrium price
90 is the equilibrium quantity
The market equilibrium point (q,p);
(90,65)
Explanation
Supply function
2p-q-30=0
Demand function
(p+10)(q+30)=8400
Solve for supply function q,
q = 2p-30 -> eq.1
Substitute eq.1 to demand function;
(p+10)(2p-30+30)=8400
(p+10)(2p)=8400
2p2+20p-8400=0 ;divide by 2 to simplify
p2+10p-4200=0; find the roots by completing the square
