A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

DF001

  • one year ago

Need help with subtracting rational expression with unlike denominators.

  • This Question is Closed
  1. surry99
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Please post your question

  2. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\frac{ 4a-2 }{ 3a+12 } - \frac{ a-2 }{ a+4 }\]

  3. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Hi, do I multiple the denominators to the opposite fraction of the numerator and denominator?

  4. surry99
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Since you need a common denominator, you would have to multiply the first term (top and bottom ) by a+4...With this in mind what do you think you will then need to multiply the second term by (top and bottom)?

  5. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\frac{ (a+4)(4a-2) }{ (a+4)(3a+12) } - \frac{ (3a+12)(a-2) }{ (3a+12)(a+4) }\]

  6. surry99
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    Great now you can simplify. Do you know how?

  7. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\frac{ (a+4)(4a-2) - (3a+12)(a-2) }{ (3a+12)(a+4) }\]

  8. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Do I distribute by foiling?

  9. surry99
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    u bet.

  10. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    :D

  11. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Does the denominator stay that way (3a+12)(a+4)

  12. surry99
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    yes

  13. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thank you

  14. surry99
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    you are welcome!

  15. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    above is correct but whenever you can work with the lowest terms

  16. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1441164057159:dw|

  17. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1441164261944:dw|

  18. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thank you Triciaal. I don't work well with LCD so I stick with multiplying both fractions by opposite denominators. I hope that works

  19. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    when you have different denominators find the lowest common denominator to work with when one is a factor of the other you do not multiply by the common factor twice

  20. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    as I stated first that is correct but it can get cumbersome and in most cases you have to divide later to get the simpliest form

  21. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    What I try to do is to make the two denominators the same when they are unlike

  22. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1441164516899:dw|

  23. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    if it was (1/2)-(3/4), can I make the denominators the same

  24. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1441164577980:dw|

  25. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    im just wondering if that works like the lcd way

  26. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1441164659366:dw|

  27. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1441164679597:dw|

  28. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1441164707541:dw|

  29. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1441164746085:dw|

  30. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1441164751381:dw|

  31. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So the LCD way and same denominator works the same way?

  32. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    the L means lowest

  33. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yes

  34. DF001
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thank you Triciaal. I wouldn't have known this since my professor isn't a native English speaker. :(

  35. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    you are welcome and it is always ok to do it "your" way whatever is easier for you

  36. triciaal
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1441165985738:dw|

  37. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.