Title  College Algebra
Answer/Discussion to Practice Problems
Tutorial 11: Complex Rational Expres
sions

WTAMU > Virtual Math Lab > College Algebra > Tutorial 11: Complex Rational Expressions Answer/Discussion to 1a Step 1:   If needed, rewrite the numerator and denominator so that they are each a single fraction.

 Combining only the numerator we get: *Rewrite fractions with LCD of y

 Combining only the denominator we get: *Rewrite fractions with LCD of y

 Putting these back into the complex fraction we get: *Write numerator over denominator

 AND Step 3: If needed, simplify the rational expression. *Rewrite div. as mult. of reciprocal     *Divide out a common factor of y         *Excluded values of the original den.

 Note that the values that would be excluded from the domain are 0 and -1/2.  These are the values that make the original denominators equal to 0. Answer/Discussion to 1b Step 1: Multiply the numerator and denominator of the overall complex fractions by the LCD of the smaller fractions.

 The denominators of the numerator's fractions have the following factors:  The denominators of the denominator's fractions  have the following factors:  Putting all the different factors together and using the highest exponent, we get the following LCD for all the small fractions: Multiplying numerator and denominator by the LCD we get: *Mult. num. and den. by x(x +3)

 Step 2: If needed, simplify the rational expression. *Factor the GCF of 2 *No common factors to divide out   *Excluded values of the original den.

 Note that the values that would be excluded from the domain are 0, -3 and -7/2.  These are the values that make the original denominators equal to 0.

WTAMU > Virtual Math Lab > College Algebra > Tutorial 11: Complex Rational Expressions

Last revised on Dec. 15, 2009 by Kim Seward.
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