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Subtract. Write fractions in simplest form. 12/7 - (-2/9) =

User Beertastic
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1 Answer

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You have to subtract the fractions:


(12)/(7)-(-(2)/(9))

You have to subtract a negative number, as you can see in the expression, both negatives values are together. This situation is called a "double negative" when you subtract a negative value, both minus signs cancel each other and turn into a plus sign:


(12)/(7)+(2)/(9)

Now to add both fractions you have to find a common denominator for both of them. The fractions have denominators 7 and 9, the least common dneominator between these two numbers is the product of their multiplication:

7*9=63

Using this value you have to convert both fractions so that they have the same denominator 63,

For the first fraction 12/7 multiply both values by 9:


(12\cdot9)/(7\cdot9)=(108)/(63)

For the second fraction 2/9 multiply both values by 7:


(2\cdot7)/(9\cdot7)=(14)/(63)

Now you can add both fractions:


(108)/(63)+(14)/(63)=(108+14)/(63)=(122)/(63)

User Hemisphera
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