# Day 18 – Addition & Subtraction of Rational Expressions

### TEXT: Intermediate Algebra by Miller, O’Neill & Hyde

Day 18 – Addition & Subtraction of Rational Expressions

We can easily add or subtract 2 rational expressions that have the same denominator using one of the following: If the denominators are not the same, then find the Least Common Multiple (LCM) of the Denominators, better known as the Least Common Denominator (LCD): Once the LCD is found then you must multiply the numerator and denominator of a particular fraction by whatever factors are needed to get the denominator to be the common one. Once the denominators are the same, then proceed as before: Two examples adding 2 rational expressions with monomial denominators:

An example subtracting 2 rational expressions with monomial denominators:

One example with more general denominators:

### 2 Responses to Day 18 – Addition & Subtraction of Rational Expressions

1. zytasia Gaines says:

No Matter how much i pratice its like i have to keep going back to my notes to compare with the homework i wish there was an easier way to remember the difference between mutiply divide and subtract its very confusing

2. awiltshire says:

Pro. halleck

So I’m gonna watch the videos, see if I get it