Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

alyssababy7

Use Cramer's rule to solve the system. 2x + 4y - z = 32 x - 2y + 2z = -5 5x + y + z = 20 A. {( 1, -9, -6)} B. {( 2, 7, 6)} C. {( 9, 6, 9)} D. {( 1, 9, 6)}

  • one year ago
  • one year ago

  • This Question is Closed
  1. brandonloves
    Best Response
    You've already chosen the best response.
    Medals 0

    we can start by clearing the z on the first two for starters. we do that by multiplying 2 to the first problem which makes it 4x+8y-2z=44 and then add it to the second

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

    I got 5x+6y=39

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

    then multiply the last one times -2 so the z's will cancel

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

    Cramer's Rule? Well, I suppose we could simplify it a little, first, but that is a little unusual. You have four 3x3 determinates in your future.

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

    or you could do it that way. both take about as long to me...

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

    I see, so we're just ignoring problem statements. :-(

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

    2x + 4y - z = 32 x - 2y + 2z = -5 5x + y + z = 20 \[\Delta = \left| \begin{matrix}2 & 4 &-1\\ 1 & -2 & 2 \\ 5 &1 & 1\end{matrix}\right|=...\] \[\Delta _{x} = \left| \begin{matrix}32 & 4 &-1\\ -5 & -2 & 2 \\ 20 &1 & 1\end{matrix}\right|=...\] \[\Delta _{y} = \left| \begin{matrix}2 & 32 &-1\\ 1 & -5 & 2 \\ 5 & 20 & 1\end{matrix}\right|=...\] \[\Delta _{z}= \left| \begin{matrix}2 & 4 & 32\\ 1 & -2 & -5 \\ 5 &1 & 20\end{matrix}\right|=...\] \[x =\frac{\Delta _{x}}{\Delta}\]\[y =\frac{\Delta _{y}}{\Delta}\]\[z =\frac{\Delta _{z}}{\Delta}\] Haven't used Cramer's Rule for long :(

    • one year ago
    • Attachments:

See more questions >>>

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.