The price of a particular model car is 35000 today and rises with at a constant rate of 700 per year. How much will a new cost in 6 years? Identify the independent and dependent variables. Write an equation for the linear function and use it to answer the given question.
Solution:-
The quantities related by a function are called variables because they vary.
The independent variable is time in years.
The dependent variable is the car cost.
Use the slope-intercept from of an equation, y = mx + b to develop a model for the given data.
Remember that slope, m, can be interpreted as the rate of change of the dependent variable per unit change in the independent variable.
Slope = 
Read the problem statement and find the slope, or the rate of increase of the car cost per year.
m = 700
Read the word problem again and find the y-intercept, b.
The y-intercept, b, in the equation can stand for the present cost of the car.
b = 35000
Use the slope-intercept from of an equation, to write the function p. Substitute 700 for m and 35000 for b.
P = 700x + 35000
Use the equation for the linear function p to find a new car cost after 6 years.
Substitute 6 for x in the equation.
P = 700x + 35000
= 700*6 + 35000
= 39200
Therefore, the price of the car in 6 years will be 39200.