Find value of the Y-intercept for the Supply curve as well as values of X- and Y-intercepts for the two Demand curves. Draw a graph to illustrate your answers:

Qd=300-2P+4I

Qs=3P-50

a) I = 25,

=300-2P+4(25) = 300-2P+100 = 400-2P

Qd=Qs

400-2P=3P-50

5P=450

P=90

Qd=300-2(90)+4(25) = 300-180+100 = 220

Qs=3(90)-50=270-50=220

Quantity is 220 and price is $90 if I=25.

b)

If I = 50,

=300-2P+4(50) = 300-2P+200 = 500-2P

Qd=Qs

500-2P=3P-50

5P=550

P=110

Qd=300-2(110)+4(50) = 300-220+200 = 280

Qs=3(110)-50=330-50=280

Quantity is 280 and price is $110 if I=50.