Why is the LCD of 5/2x and 7/5x3y 10x^2y and not 10x3y?

  • Thread starter marcflores
  • Start date
  • Tags
    Arithmetic
In summary, the conversation is about finding the lowest common denominator of two fractions, 5/2x and 7/5x3y. The correct LCD is 10x3y, but the book shows it as 10x^2(y), which may be a typo or poor printing. The individuals discussing also question the similarity of 5x^2y to 5x3y, suggesting it may have been a mistake.
  • #1
marcflores
38
0

Homework Statement



LCD of 5/2x and 7/5x3y

Homework 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)!

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:
Physics news on Phys.org
  • #2
Do you mean
[tex] \[
\frac{5}{{2x}}\quad and\quad \frac{7}{{5x3y}}
\]
[/tex]

If so, then LCD is [tex] \[
2 \cdot 3 \cdot 5 \cdot xy
\]
[/tex]
 
  • #3
Yeah, I agree with 30xy if the denominators are 2x and 15xy each...
 
  • #4
marcflores said:

Homework Statement



LCD of 5/2x and 7/5x3y
...

I figured, the lowest common multiple of 2x and 5x3y is 10x3y. For some reason, my book shows the answer as 10x^2(y)!
...
Is it a typo or am I just going crazy?
It's either a typo or poor quality printing.

Does [itex]5x^2y [/itex] look a little bit like [itex]5x3y[/itex]? I'll bet the book meant the former.
 
  • #5
symbolipoint said:
Do you mean
[tex] \[
\frac{5}{{2x}}\quad and\quad \frac{7}{{5x3y}}
\]
[/tex]

If so, then LCD is [tex] \[
2 \cdot 3 \cdot 5 \cdot xy
\]
[/tex]


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.
 

FAQ: Why is the LCD of 5/2x and 7/5x3y 10x^2y and not 10x3y?

What is basic arithmetic?

Basic arithmetic is the branch of mathematics that deals with the four basic operations: addition, subtraction, multiplication, and division. It is the foundation for more advanced mathematical concepts.

What are the four basic operations?

The four basic operations are addition, subtraction, multiplication, and division. Addition is combining two or more numbers to find their sum. Subtraction is taking away one number from another to find the difference. Multiplication is repeated addition, and division is the inverse of multiplication.

How do I solve a basic arithmetic problem?

To solve a basic arithmetic problem, you must follow the order of operations, which is parentheses, exponents, multiplication and division (left to right), addition and subtraction (left to right). You can also use the PEMDAS acronym to remember this order.

What are some common mistakes when solving basic arithmetic problems?

Some common mistakes when solving basic arithmetic problems include incorrect order of operations, forgetting to carry or borrow when performing addition or subtraction, and mistaking multiplication for addition when using the distributive property.

How can I improve my basic arithmetic skills?

The best way to improve your basic arithmetic skills is through practice. You can also use online resources, such as math games and practice worksheets, to strengthen your understanding of basic arithmetic concepts. Additionally, seeking help from a tutor or teacher can also be beneficial.

Back
Top