Here's how to subtract 6/7 from 8/9:
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Step 1We can't subtract two fractions with different denominators. So you need to get a common denominator. To do this, you'll multiply the denominators times each other... but the numerators have to change, too. They get multiplied by the other term's denominator. So we multiply 8 by 7, and get 56. Then we multiply 6 by 9, and get 54. Next we give both terms new denominators -- 9 × 7 = 63. So now our fractions look like this:
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Step 2Since our denominators match, we can subtract the numerators. 56 − 54 = 2 So the answer is:
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Step 3Last of all, we need to simplify the fraction, if possible. Can it be reduced to a simpler fraction? To find out, we try dividing it by 2... Nope! So now we try the next greatest prime number, 3... No good. 3 is larger than 2. So we're done reducing. There you have it! The final answer is:
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