From the course: Test Prep: GRE
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Adding and subtracting fractions
- [Voiceover] This video I'll talk about fractions just in terms of adding and subtracting them, and also I'll go into how to reduce and expand the fraction a little bit. So let's just talk about adding fractions. The easiest way to add fractions is if you have two fractions that have the same denominator. So let's say I had one fourth plus two fourths. That's easy; I just go straight across, one plus two is three, and then I keep the denominator the same. Easy, and the same thing happens with subtracting fractions. Let's say I had five sixths minus two sixths, well, that would be three sixths. Again, we would just go straight across in the numerator, five minus two is three, keep the denominator the same. But what if I had a situation like this? What if I had one third plus one half? Well, that's a problem for a minute here. We can't just add these two unless they have a common denominator like we did over here. So what we do is we give them a common denominator. The easy way to do…
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Contents
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Integers: Factors, multiples, and remainders2m 7s
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Integers: Even and odd and primes3m 29s
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Order of operations2m
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Number properties3m 46s
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Adding and subtracting fractions3m 36s
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Multiplying and dividing fractions1m 22s
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Decimals3m 9s
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Mental percents2m 55s
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Taking percents and increasing by percents1m 55s
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Percent change3m 36s
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Ratios and proportions4m 20s
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Direct proportion and inverse variation3m 6s
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Exponents2m 7s
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More exponents2m 7s
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Fake exponent rules2m 10s
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Scientific notation3m 32s
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Square roots3m 45s
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Cube and fourth roots2m 34s
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