Quantcast

A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

katie2212

  • 3 years ago

Use elimination to solve the system. What is the value of x? 4x + 7y = -14 and 8x + 5y = 8

  • This Question is Closed
  1. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Hint: Multiply everything in the first equation by -2 to go from 4x + 7y = -14 to -8x - 14y = 28

  2. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    So you now have the two equations -8x - 14y = 28 8x + 5y = 8

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

    That's solving for x first and then plugging it back to get y. I thought that the OP wanted to do it from that one step.

  4. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    you can go a number of ways, you can multiply the top equation by 5 and the bottom equation by -7, then add

  5. katie2212
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    im just getting more confused

  6. jefferyflow123go
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I believe the answer is -14.

  7. katie2212
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    these are the options. 3.5 -1.5 8 -4

  8. jefferyflow123go
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Oh then i bet the answer is -5

  9. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Do you see how I went from 4x + 7y = -14 to -8x - 14y = 28

  10. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    it's not -5

  11. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    please don't give away the (incorrect) answer

  12. jefferyflow123go
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    sorry, if you would just give her the right answer, i would be able to go on with my day. As would she

  13. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    I'm providing hints and trying to walk her through it (without giving it all away)

  14. jefferyflow123go
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    No matter how many hints your provide she doesn't care. she just wants the answer

  15. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    well that's not what this site is for, I'm sry

  16. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    if you keep this behavior up jefferyflow123go you will be reported (and possibly suspended/banned)

  17. katie2212
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    its hard for me too understand..im trying. i learn better in a class room thats why i am having trouble with my online class

  18. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    its ok, you don't have to understand everything at once katie2212

  19. katie2212
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    but i have to understand if i want to finishe this exam.

  20. jefferyflow123go
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Sorry for hekping. My mom always taught me to hekp and have pride in my work, so trying to be of assistance. I didn;t realize that you can be the only genious here. If you were that smart you'd know that she doesn't understand your hints and just wants the answer.

  21. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    that's not helping though, you may think it is...but it's not

  22. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    if you want, you can provide the steps so she can learn from them

  23. katie2212
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    okay will you guys please stop arguing and just help me!

  24. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    ok I'll give steps on this one and hopefully it will be enough to answer similar ones, sound good?

  25. jefferyflow123go
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    IS your refrigderator running ? IF SO GO CATCH IT

  26. katie2212
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yes thank you

  27. jefferyflow123go
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    My momma once told me, a fast runna' is the best runnna'

  28. katie2212
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    jeffery if youre not going to help please get out.

  29. jefferyflow123go
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    BUT IM JUST TRYNA HELP YOU. ILL CATCH YOUR FRIDGE FR YOU.

  30. jefferyflow123go
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    What did the bison say to his son when he left for college? Bi-son

  31. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    4x + 7y = -14 ... Start with the first equation -2(4x + 7y) = -2*(-14) ... Multiply both sides by -2 -8x - 14y = 28 ... Distribute and multiply --------------------- So 4x + 7y = -14 is the same as -8x - 14y = 28 --------------------- This means that the system 4x + 7y = -14 8x + 5y = 8 becomes -8x - 14y = 28 8x + 5y = 8 Now add the two equations: -8x - 14y = 28 8x + 5y = 8 -------------- 0x - 9y = 36 which means that -9y = 36 Solve for y to get -9y = 36 y = 36/(-9) y = -4 Now that we know that y = -4, we can use this to find x. Pick on any equation, plug in y = -4 and solve for x 4x + 7y = -14 4x + 7(-4) = -14 4x - 28 = -14 4x = -14 + 28 4x = 14 x = 14/4 x = 7/2 x = 3.5 So the value of x is x = 3.5

  32. jefferyflow123go
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    IM SO PUN-NY

  33. jefferyflow123go
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    IM A MaTH WIZ

  34. katie2212
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thank you Jim

  35. jefferyflow123go
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yanno wizard like Harry Potter

  36. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    The idea here is to get the x coefficients equal and opposite. Then you add the equations. Doing so will cancel out the x terms so you can solve for y

  37. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    then you use that value of y to find x

  38. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    you've been reported jefferyflow123go, have a nice day

  39. jefferyflow123go
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    you too good sir(:

  40. jim_thompson5910
    • 3 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    good luck with that one, I don't spam and harass others so your claim will be without merit

  41. 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.