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Basic Algebra/Working with Numbers/Subtracting Rational Numbers

VocabularyEdit

LessonEdit

Subtracting fractions when the denominators are equal is also easy

 

Notice that when the denominators are the same for either adding or subtracting fractions we only add or subtract the numerators. With this in mind we can now use the techniques learned in Lesson 4 to subtract more complex fractions by finding the factors of the following fractions

 

We can now see that multiplying 456 by 5 and 570 by 4 gives the smallest possible denominator

 

Now the question is, is this fraction irreducible? We know the factors in the denominator so checking if 361 is divisible by the numbers 2, 3, 5, 19 will show that 361/19 = 19 therefore

 

Which is now an irreducible fraction.

Example ProblemsEdit

 

 

 

 

 

 

 

 

Practice GamesEdit

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Practice ProblemsEdit

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Subtracting Rational Numbers
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