Question

suppose that the demand function or schedule is given by the linear equation p = 300 - qd and the supply equation by p =60 + 2 qs (a) find the equilibrium price and quantity (b) suppose the supply curve slop prices from 2 qs to 3 qs (C) find the new equilibrium price and quantity (d) find the equilibrium position graphically?

Answer 1

$(a)\\ Qd=300-p\\ Qs=p-60\div2\\ Qd=Qs\\ 300-p=p-60\div2\\ 600-2p=p-60\\ 660=3p\\ p=110\\ Qd=Qs=300-p\\ =300-110\\=190$

(b)

$p=60+3Qs\\ Qs=p-60\div3\\ Qd=300-p\\ Qs=Qd\\ p-60\div3=300-p\\ p-60=900-3p\\ 4p=900+60\\ p=960\div4\\ p=240$