In order to find the market equilibrium set Qd= Qs which is equal to
100 - 2P = 4P - 80
Subtracting 100 from both side you will get
- 2P = 4P - 80 -100
- 2P = 4p -180
Now subtracting 4P from both sides you will get
- 2P - 4P = -180
-6p = - 180
Dividing both sides by -6 you will get
-6/-6 P = -180/-6
P = 30 >>answer
If P= 30 then
Qs = 4(30)-80
=120-80
=40 >>answer
Qd = 100 - 2(30)
=100 - 60
= 40
Qs = Qd which is 40 = 40
100 - 2P = 4P - 80
Subtracting 100 from both side you will get
- 2P = 4P - 80 -100
- 2P = 4p -180
Now subtracting 4P from both sides you will get
- 2P - 4P = -180
-6p = - 180
Dividing both sides by -6 you will get
-6/-6 P = -180/-6
P = 30 >>answer
If P= 30 then
Qs = 4(30)-80
=120-80
=40 >>answer
Qd = 100 - 2(30)
=100 - 60
= 40
Qs = Qd which is 40 = 40