At price of $3.10 per gallon, the weekly demand by consumers for gas is 42 gallons. If price rises to $3.25 per gallon, weekly demand drops to 39 gallons. Find formula for q, weekly quantity of gas demanded in terms of p, price per gallon, assuming demand is linear.
Please show with steps, I know a slope would have to be found?
Please show with steps, I know a slope would have to be found?
-
slope = m = (42 - 39)/(3.1 - 3.25)
m = - 20
- 20 = (q - 39)/(p - 3.25)
- 20*p + 65 = q - 39
q = - 20*p + 104, answer!
m = - 20
- 20 = (q - 39)/(p - 3.25)
- 20*p + 65 = q - 39
q = - 20*p + 104, answer!
-
x1 = 3.10 y1 = 42
x2 = 3.25 y2 = 39
Slope is (y1 - y2)/(x1 - x2) = 3/(-0.15) = -20
y = (-20)x + c
substitute one pair of readings to find c
42 = -(20)*3.10 + c
42= -62 + c
c = 104
y = -20x + 104
x2 = 3.25 y2 = 39
Slope is (y1 - y2)/(x1 - x2) = 3/(-0.15) = -20
y = (-20)x + c
substitute one pair of readings to find c
42 = -(20)*3.10 + c
42= -62 + c
c = 104
y = -20x + 104
-
what is q?