Question

For the following pairs of supply and demand equations, where x represents the quantity

demanded in units of a thousand and p is the unit price in dollars, find the equilbrium point.

(a) 0 = −2x

2 − p+80 and 0 = 15x− p+30

(b) 11p+3x = 66 and 2p

2 + p−x = 10

Answer 1

a)

$$-2x^2-p+80=0$$

$$15x-p+30=0$$

$$-2x^2-15x+50=0$$

$$2x^2+15x-50=0$$

$$x=2.5$$

$$p=67.5$$

b)

$$11p+3x=66$$

$$2p^2+p-x=10$$

$$3p^2+7p-48=0$$

$$x=11$$

$$p=3$$