The price-demand equation for gasoline is 0.1 x + 4 p = 85 where p is the price per gallon in dollars and x is the daily demand measured in millions of gallons.a. What price should be charged if the demand is 40 million gallons?b. If the price increases by $0.4 by how much does the demand decrease?

Respuesta :

Answer:

a. The price that should be charged if the demand is 40 million gallons is $20.25.

b. The demand decreases by 16 millions of gallons.

Step-by-step explanation:

We know that the price-demand equation for gasoline is given by

[tex]0.1 x + 4 p = 85[/tex]

where

p is the price per gallon in dollars and

x is the daily demand measured in millions of gallons.

a. To find what price should be charged if the demand is 40 million gallons you must

Solve for p,

[tex]0.1x\cdot \:10+4p\cdot \:10=85\cdot \:10\\x+40p=850\\40p=850-x\\p=\frac{850-x}{40}[/tex]

We know that the demand is 40 million gallons (x = 40). So,

[tex]p=\frac{850-40}{40}=\frac{81}{4}=20.25[/tex]

b. To find how much does the demand decrease when the price increases by $0.4 you must

Solve for x,

[tex]0.1x\cdot \:10+4p\cdot \:10=85\cdot \:10\\x+40p=850\\x=850-40p[/tex]

We know that the price increases by $0.4. So,

[tex]-40\left(0.4\right)=-16[/tex]

The demand decreases by 16 millions of gallons.