Pre calculus problem.... ?

Question

A certain person's salary is linearly related to the number of years he/she has worked for a particular company. The starting salary for the first year was $20,000 per year and 3 years later the salary had increased by $6,000. Find a function S9x) that describes the salary of this individual with respect to the x number of years of service. Predict the salary of this individual after 20 years of service to this company.

Answer 1

Since the function is assumed to be linear, you know it has the form:

y = mx + c  (Eqn. 1)

or in alternative form:

y-y1 = m(x-x1) where (x1,y1) is a point on the line

In this case y --> Salary in $

and x --> years worked for the company

You can find the slope since you know two points on the line:

(0, 20000)

(3,26000)

Find the slope and since the first ordered pair IS the y-intercept you have both m and c from Eqn. 1.

Once you have the function, plug in the x-value (20) to find the salary after 20 years.