SOLUTION: when is it necessary to find the least common denominator of two rational expressions? Describe the process for finding the LCD of two rational expressions. How is factoring relat

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Question 749651: when is it necessary to find the least common denominator of two rational expressions? Describe the process for finding the LCD of two rational expressions. How is factoring related to this process?

Found 2 solutions by stanbon, Alan3354:
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
when is it necessary to find the least common denominator of two rational expressions?
Ans: when you are adding or subtracting fractions with different denominators.
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Describe the process for finding the LCD of two rational expressions.
Example:
3/8 + 5/10
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To find the lcd:
8 = 2^3
10 = 2*5
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lcd must contain each of the prime factors is its highest power
lcd = 2^3*5 = 8*5 = 40
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Rewrite each fraction with the lcd as its denominator:
(3/8) = (3/8)(5/5) = 15/40
(5/10 = (5/10)(4/4) = 20/40
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Add the equivalent fractions that have the same denominator to get:
= 35/40
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How is factoring related to this process?
Comment: See the example.
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Cheers,
Stan H.
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Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website!
when is it necessary to find the least common denominator of two rational expressions?
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It isn't.
You can add or subtract when the denominators are the same, a Common Denominator.
It doesn't have to the the Least, as long as it's common.