Car rental company charges $30 a day and 12 cents a mile for its cars. (a) write a formula for the dollar cost, c, of renting a car as a function of the number of days, d, and the number of miles driven, m.

To write an expression for a day you can obviously just make up one by putting in m as the number of miles. So to calculate the cost for m miles you can write m * (0.12) and more over at the end we have to add the 30$ so the expression equals to 30 + m (0.12).

Now for more days we can simply multiply it by d. So d*( 30 + m (0.12)) for some days d.

FInally, c = d*( 30 + m (0.12)).

answer: the price of one pound cabbage = $ 0.8

the point (10,8) represents that the cost of 10 pounds cabbage is $ 8

step-by-step explanation:

since, here is a proportional relation between the number of pounds of cabbage (x) and the price in dollars (y).

therefore, we can write,

⇒ y = k x

where k is the constant of proportionality.

now, point (5,4) is in the line.

thus, it will satisfies the above equation of line.

⇒ 4 = 5 k

⇒ k = 0.8

thus, the equation of the line is,

y = 0.8 x

a) for x = 1,

y = 0.8

therefore, the cost of one pound of cabbage is 0.8 dollars.

b) in the below graph (10,8) represents that the cost of 10 pounds of cabbage is 8 dollars.