Addition and Subtraction of Rational Expressions
Key Questions
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You can keep the same denominator and add or subtract the numerators.
#a/c+b/c={a+b}/c# and#a/c-b/c={a-b}/c#
I hope that this was helpful.
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The least common denominator is the least common multiple of denominators.
Example
Find the least common denominator to compute:#1/3+1/4-1/6# Let us observe:
Multiples of
#3# :#3,6,9# , 12,#15,...#
Multiples of#4# :#4,8# ,12,#16,...#
Multiples of#6# :#6# ,12,#18,...# ,So, the least common multiple of
#3# ,#4# , and#6# is#12# .Hence,
#1/3+1/4-1/6=4/12+3/12-2/6={4+3-2}/12=5/12#
...
I hope that this was helpful. -
You need to put each term over a common denominator by multiplying each term by the appropriate form of
#1# or#n/n# -
#A/B + C/D = (AD + BC)/(BD)# and
#A/B - C/D = (AD - BC)/(BD)#
Questions
Rational Equations and Functions
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Inverse Variation Models
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Graphs of Rational Functions
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Division of Polynomials
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Excluded Values for Rational Expressions
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Multiplication of Rational Expressions
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Division of Rational Expressions
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Addition and Subtraction of Rational Expressions
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Rational Equations Using Proportions
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Clearing Denominators in Rational Equations
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Surveys and Samples