Question

The cost of renting a car for a day is $0.70 per mile plus a $20 flat fee

(a) write an equation to represent this relationship. Let x be the number of miles driven and y be the total cost for the day.
(b) what does the graph of this equation form on a coordinate plain.
(c) what is the slope and the y-intercept of the graph of the relationship? explain.

Answer 1

a) y = .70x + 20

-To find this, use the rate as x since it will change based on the number of miles. Since 20 is a flat fee, it can be added at the end as a constant.

b) This graph forms a straight line.

-This is because the answer in a is a linear equation.

c) The slope is .70 and the y-intercept is 20.

-For this one, the y-intercept is always the constant at the end of the equation and the slope is the coefficient of x.