Quantcast

A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

gjhfdfg

  • 2 years ago

Gaussian elimination method help?

  • This Question is Closed
  1. gjhfdfg
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I have absolutely know idea how to solve this problem using it, 3x - 2y + 2z - w = 2 4x + y + z + 6w = 8 -3x + 2y - 2z + w = 5 5x + 3z - 2w = 1 Wants me to find the solution

  2. gjhfdfg
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I mean no instead of know. *face palm*

  3. tyteen4a03
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    The matrix version or the simple "moving variables around" version?

  4. gjhfdfg
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I believe its the 'simple' moving variables around version

  5. tyteen4a03
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    I just threw this into Wolfram|Alpha, and it didn't give me any value results. Do you need value results?

  6. gjhfdfg
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Nope, it says find the solution or state that none exists./ So I guess there isnt a solution

  7. tyteen4a03
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Oh, then I'll show you why there isn't one then. When doing the simple version of Gaussian elimination, always look for "bare" variables first (variables that has a coefficient of 1, otherwise known as "that variable with no numbers"). In this case: 3x - 2y + 2z - w = 2 (1) 4x + y + z + 6w = 8 (2) -3x + 2y - 2z + w = 5 (3) 5x + 3z - 2w = 1 (4) In this case, we notice that in Equation 1 and 3, both w are bare (although there's a minus sign before the w in Eq. 1). Shift w around in Eq. 1 to make it positive again. Now change the subject: 3x - 2y + 2z - w = 2 becomes w = 3x - 2y + 2z - 2 and -3x + 2y - 2z + w = 5 becomes w = 5 + 3x - 2y + 2z. Now that w is (sort of) found, hook them together: 3x - 2y + 2z - 2 = 5 + 3x - 2y + 2z. You see that after simplifying you're left with -2 = 5, which is obviously impossible. Therefore, there is no solution since two of the so-called "related equations" contradict each other.

  8. gjhfdfg
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Got it, thank you.!

  9. 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.