# Homework Help: Basic Arithmetic Problem!

1. Aug 5, 2007

### marcflores

1. The problem statement, all variables and given/known data

LCD of 5/2x and 7/5x3y

2. Relevant equations

Lowest common denominator is also lowest common multiple:

(2)(x)
(5)(x)(3)(y) =
(10)(x)(3)(y)

I figured, the lowest common multiple of 2x and 5x3y is 10x3y. For some reason, my book shows the answer as 10x^2(y)!

3. The attempt at a solution

At this point, I don't know why I didn't come up with the same solution as the book.

This is from the Pre-Algebra text "Preparation for Algebra" Nanney/Cable. I bought this from my college to brush up on a lot of fundamental skills I'd forgotten and this was an exercise in the beginning of the book. Is it a typo or am I just going crazy?

Last edited: Aug 5, 2007
2. Aug 5, 2007

### symbolipoint

Do you mean
$$$\frac{5}{{2x}}\quad and\quad \frac{7}{{5x3y}}$$$

If so, then LCD is $$$2 \cdot 3 \cdot 5 \cdot xy$$$

3. Aug 5, 2007

### physgirl

Yeah, I agree with 30xy if the denominators are 2x and 15xy each...

4. Aug 6, 2007

### Gokul43201

Staff Emeritus
It's either a typo or poor quality printing.

Does $5x^2y$ look a little bit like $5x3y$? I'll bet the book meant the former.

5. Aug 6, 2007

### marcflores

Yes, that's how I meant it. But I also agree with Gokul43201 in that it might be a typo or poor printing because it seems that all the other exercises in the section have a certain likeness to it... this one seemed off.

Thanks for the help.