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

K.marie

How do you do this linear system? {3x+y+2z=3 X-2y+3z=1 4x-8y+12z=7

  • one year ago
  • one year ago

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

    is it matrices or which topic

    • one year ago
  2. jim_thompson5910
    Best Response
    You've already chosen the best response.
    Medals 0

    Look at equation 1 where you see the term 1y or just y isolate that y to get 3x+y+2z=3 y=3-3x-2z

    • one year ago
  3. jim_thompson5910
    Best Response
    You've already chosen the best response.
    Medals 0

    now go to the other 2 equations and replace y with 3-3x-2z

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

    let @jim_thompson5910 take care of that

    • one year ago
  5. jim_thompson5910
    Best Response
    You've already chosen the best response.
    Medals 0

    so equation 2 goes from x-2y+3z=1 to x-2(3-3x-2z)+3z=1 x-6+6x+4z+3z = 1 7x-6+7z = 1 7x+7z = 1+6 7x+7z = 7 7(x+z) = 7 7(x+z)/7 = 7/7 x+z = 1

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

    oh my

    • one year ago
  7. jim_thompson5910
    Best Response
    You've already chosen the best response.
    Medals 0

    Now focus on Equation 3 4x-8y+12z=7 4x-8(3-3x-2z)+12z=7 4x-24+24x+16z+12z=7 28x-24+28z=7 28x+28z=7+24 28x+28z=31

    • one year ago
  8. jim_thompson5910
    Best Response
    You've already chosen the best response.
    Medals 0

    After doing all that, things boil down to these 2 equations x+z = 1 28x+28z=31

    • one year ago
  9. jim_thompson5910
    Best Response
    You've already chosen the best response.
    Medals 0

    use any method to solve that new system of equations for x and z once you have x and z, you can use them both to find y

    • 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.