The price-demand equation for gasoline

Question

how much does the demand decrease

Answer 1

Price demad equation 0.2x+5p = 40

a) 0.2x+5p = 40

5p = 40-0.2x

p = (40-0.2x)/5

p= (40-0.2*20)/5 = $7.2

The price is p=$7.2

b)

Write the price-demand equation in terms of x.

0.2x+5p = 40

0.2x =40-5p

x = (40-5p)/0.2=200-25p

The slope of the equation is -25

x = -25p =-25(0.4) =-10

The demand function is decreased by 10 millions of gallons