You are here:

Word Problems/Quadratic Function

Advertisement


Question
12
3. A new television depreciates $120 per year, and it is worth $515 after seven years. Find a
function that describes the value of this television, if x is the age of the television in years. What
will the cost of the television be in thirteen years? If you had bought the television four years
ago, what was its selling price?

Answer
I do not see how this question is about quadratic functions.

"A new television depreciates $120 per year, and it is worth $515 after seven years."
total depreciation after 7 years: 7$120 = $840
Purchase price = current value + total depreciation = $515 + $840 = $1,355

"Find a function that describes the value of this television, if x is the age of the television in years."
f(x) = 1,355 - 120x

"What will the cost of the television be in thirteen years?"
13$120 > $1,355
After thirteen years, the television has no residual value.

"If you had bought the television four years ago, what was its selling price?"
I'm not sure what they mean by selling price, as the price of a new television was already found to be $1,355.
If they mean "how much could you sell it for today," its residual value is
f(4) = 1,355 - 1204 = $875

Word Problems

All Answers


Answers by Expert:


Ask Experts

Volunteer


Janet Yang

Expertise

Word problems are my favorite type of math questions! I would not feel comfortable answering questions that require specialized knowledge (Physics, Statistics, etc.) because I have not studied these in depth.

Experience

I tutor students (fifth through twelfth grades) and am a Top Contributor on Yahoo!Answers with over 24,000 math solutions.

Publications
Co-author of An Outline of Scientific Writing: For Researchers With English as a Foreign Language.

Education/Credentials
I have a Bachelor's degree in Applied Mathematics from the University of California at Berkeley, and a Master of Business Administration degree from The Wharton School.

Past/Present Clients
George White Elementary School. Homework Help program at the Ridgewood Public Library, Ridgewood, NJ. Individual students.

©2016 About.com. All rights reserved.