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# LCD?

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Unless they changed least common denominator since I went to school I think this book is confusing LCD with LCM:

http://www.wallace.ccfaculty.org/book/7.3%20LCD.pdf

My son's textbook had a similar mistake for the LCD of  x^2  and x^3.

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Yes, that is nonsense.

Examples 1, 2, 3 and 4 do not have any denominator, never mind a least one - there are no fractions.

They mean least common multiple.

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I don't know. In their examples, there's no LCD that you can get by going smaller. Sure, the LCD of 3/4 and 6/8 is 4; but in their examples, you have to go up because you can't divide down. I'm sorry if I'm not explaining it well, but it doesn't seem like an error to me.

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I don't know. In their examples, there's no LCD that you can get by going smaller. Sure, the LCD of 3/4 and 6/8 is 4; but in their examples, you have to go up because you can't divide down. I'm sorry if I'm not explaining it well, but it doesn't seem like an error to me.

But it makes no sense to speak of a denominator when the expressions (8 and 6, for example) are not fractions.

The Least Common Denominator  of the numbers 8 and 6 (ex 1) is 1.

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Ahh...I understand now. I was assuming they were talking of "denominators" of 6 and 8, and the rest in their examples. They do have fractions in their later examples, and it looks so similar to my DS's recent fraction work that my brain assumed they were obviously working with denominators of unnamed numerators in all the problems.

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