### Adding and Subtracting Rational Expressions with Unlike Denominators

The

*Least Common Multiple*, or LCM, of a set of polynomials is the polynomial of smallest degree that is a multiple of each of the polynomials in the set.To add or subtract fractions with unlike denominators, first find the LCM of the denominators. Then adjust the numerator and denominator of each fraction so that its denominator is the LCM. Finally, add or subtract the numerators and simplify the result.

Most of the time, the result will not simplify but always check to see if the numerator and denominator have any common factors.

### Adding and Subtracting Rational Expressions with Unlike Denominators

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

- Intro 0:00
- Least Common Multiple (LCM) of Polynomials 0:34
- Example
- Example
- Adding and Subtracting 4:08
- Example
- Lecture Example 1 8:13
- Lecture Example 2 10:22
- Additional Example 3
- Additional Example 4

0 answers

Post by Roman Kozulin on September 18, 2012

How did Z-2 became Z+2 in example 3 ?