alleryStart learning →The least common denominator is needed when rational expressions have denominators that are:
AAlways numbers
BAlways variables
CUnlike each other
DExactly the same
Answer & Solution
Correct answer: C. Unlike each other
1. Common denominators are only a problem when they differ.
2. Rational expressions may share a denominator or not.
3. When we add or subtract rational expressions with unlike denominators, we need common denominators.
4. Finding the least common denominator is the standard route.
_Source: OpenStax Elementary Algebra 2e (CC BY 4.0), Ch 8 'Rational Expressions and Equations', sections 8.1-8.9_
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