# Rational Expressions 1 - Introduction

Taught by YourMathGal
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Lesson Description:

This is an introduction to Rational Expressions in beginning algebra.

More free YouTube videos by Julie Harland are organized at http://yourmathgal.com

• What are rational expressions?
• How do you find the value of a rational expression when you know the value of x?
• What is the value of (x + 9)/(x - 2) when x = -3?
• What does (x^2 + 1)/(2x) equal when x = -3?
• What is the value of (2x + 11)/(x + 3) when x = -3?
• What does 5/0 equal?
• How do you know which numbers make a rational expression undefined?
• When is 5/(x - 2) undefined?
• For what values of x is (x + 5)/3x undefined?
• When is (x^2 + 1)/7 undefined?
• When is (x + 5)/(x^2 - 16) undefined?
• Why is a fraction undefined if 0 is in the denominator?
• Why can you not divide by 0?
• What does 8/0 mean?
• Why is it undefined when you divide a number by 0?
• What does 0/0 equal?
• Why is 0/0 undefined?
• #### Staff Review

• Currently 4.0/5 Stars.
This lesson shows some good examples of substituting a numerical value into some expressions to find what they equal. You also learn how to determine what values of x make a rational expression undefined. Some great examples really drive home the concepts in this lesson.