A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

which equation describes a line that is NOT parallel to the lines described by the other three equations? 1. 2x+7y=8 2. -6x-21y=-5 3.-10.5y=3x 4.y+8=(2/7)(x-7)

  • This Question is Closed
  1. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    OH MY GAWD

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

    the struggle!

  3. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Can you check the third equation?

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

    Yup thats the exact one on my test. its -10.5y=3x

  5. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Ok. Solve each equation for y and write it in the form y = mx + b. m, the number that multiplies x, is the slope.

  6. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Let's try the first one: \(2x+7y=8\) Subtract 2x from both sides: \(7y = -2x + 8\) Divide both sides by 7: \(y = -\dfrac{2}{7} x + \dfrac{8}{7} \) The slope is \(-\dfrac{2}{7} \) Now do the same to all other equations and compare their slopes.

  7. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    By "do the same to all other equations" I mean solve all other equations for y and put them in the y = mx + b form.

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

    ok so 2x+7y=8 is y=-2x/7+8/7 -6x-21y=-5 is y=-2x/7+5/21 -10.5y=3x is y=-0.28571429x and y+8=2/7(x-7) is y=2x/7-10

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

    1. slope is -2/7 2. slope is -2/7 3. slope is -0.28571429 4. slope is 2/7

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

    so is it 3? @mathstudent55

  11. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \(-6x-21y=-5\) \(-21y = 6x - 5\) \(y = -\dfrac{6}{21}x + \dfrac{5}{21} \) \(y = -\dfrac{2}{7}x + \dfrac{5}{21} \) Correct.

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

    Thankyou so much for your help!

  13. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \(-10.5y=3x\) \(y = - \dfrac{3}{10.5} x \) \(y = - \dfrac{6}{21} x \) \(y = - \dfrac{2}{7} x \) Incorrect.

  14. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    You should keep the third one as a fraction. The you will see that the third one is also -2/7. The answer is D, 2/7

  15. mathstudent55
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    1. slope is -2/7 2. slope is -2/7 3. slope is -0.28571429 = -2/7 4. slope is 2/7 The only different slope is D.

  16. 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.