8: Rational Expressions
- Page ID
- 45074
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By the end of this chapter, the student should be able to
- Evaluate rational expressions
- Obtain the excluded values of the expression
- Reduce rational expressions
- Multiply and divide rational expressions with and without factoring
- Find least common denominators
- Add and subtract rational expressions with and without common denominators
- Simplify compound rational expressions
Now that we discussed factoring to great lengths, we can introduce rational expressions where fractions contain polynomials. This chapter prepares us for future chapters when we solve rational equations and functions. Similar to fractions in arithmetic, we are concerned when the denominator is zero. Hence, we start this chapter evaluating rational expressions and determining the location of rational expressions’ excluded values.
- 8.3: Obtain the Lowest Common Denominator
- As with fractions in arithmetic, the least common denominator or LCD is the lowest common multiple (LCM) of the denominators. Since rational expressions are fractions with polynomials, we use the LCD to add and subtract rational expression with different denominators. In this section, we obtain LCDs of rational expressions.