Objective: Add and subtract rational expressions that contain like denominators.
In order to add or subtract rational expressions, both expressions must share a common denominator. If they already share a common denominator, you can add (or subtract) the numerators together and keep the common denominator. After adding (or subtracting), you must try to simplify the expression by factoring all polynomials and removing any common factors. This is that same procedure that you would do if adding or subtracting fractions.
One thing to be especially careful about when subtracting is to subtract each term of a polynomial, not just the first term. The video below will demonstrate how to add and subtract rational expressions that share a common denominator and it will highlight the important feature or distributing the negative sign when subtracting rational expressions.
By now you may be wondering how to add and subtract rational expressions when they do not share a common denominator. This process is a bit more involved and requires a lesson on its own. You'll learn how to do this in the next lesson of this unit, Lesson 4.
Complete the worksheet attachment below and then check your answers using the solutions attachment. Once you have completed these exercises, click the link to advance to the next lesson.