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

MeganDarling Group Title

Really need help! Been trying to solve for a while. 1. Solve the system by using a table. 3y=4x+7 , -4x-4y=28. These are the possible solutions:(–4, –3),(–3, –4), (4, 3),(3, 4). 2.Solve by graphing. -3x-y=-10, 4x-4y=8. possible solutions:(-1,3), (3-1), (1,3), (3,1)

  • 2 years ago
  • 2 years ago

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

    Also help with this problem : The spreadsheet shows the monthly revenue and expenses for a new business. Use the models to predict the month in which revenue will equal expenses. Possible answers: October September August May

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

    help with any of them would be really appreciated (:

    • 2 years ago
  3. L.T. Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    I think September is your answer for the second problem

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

    your estimate is as good as any haha. I have no clue so even an educated guess is better than nothing

    • 2 years ago
  5. MeganDarling Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    I honestly just suck horribly at solving systems of any sort x.x

    • 2 years ago
  6. L.T. Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    I answered it that way by reproducing the pattern of increase in the revenue and expense columns--that is, by adding differences in a row. Does that sound legitimate?

    • 2 years ago
  7. MeganDarling Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    Sounds alright to me haha

    • 2 years ago
  8. L.T. Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    I think I can solve the system, but I'm not sure what is meant by table. Is it all right if you use substitution and elimination?

    • 2 years ago
  9. MeganDarling Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    I would just really like some help with the 1st two because there are lot's of other questions like them, including on upcoming tests. That I really don't want to get wrong :/

    • 2 years ago
  10. MeganDarling Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    Yeah that's what I was trying to do. I however looked up solving solutions on google and it showed a way to do it where you used a graph to figure out where the two lines crossed. It didn't make sense with my equation though.

    • 2 years ago
  11. satellite73 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    \[-3x-y=-10\]\[ 4x-4y=8\] first equation is the same as \(y=-3x+10\) so you can replace \(y\) in the second equation by \(-3x+10\) with judicious use of parentheses you get \[4x-4(-3x+10)=8\] and now you have one equation and one variable to solve

    • 2 years ago
  12. satellite73 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    you get \[4x+12x-40=8\] \[16x-40=8\] \[16x=48\] \[x=48\div 16=3\]

    • 2 years ago
  13. MeganDarling Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    As long as it end up with an x and a y and they are one of the options above I really don't understand why it matters so much how we got it haha. I suppose in some cases it really matters but.. Thanks satellite that makes sense. I'll try writing it out.

    • 2 years ago
  14. satellite73 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    hope the steps are claere

    • 2 years ago
  15. MeganDarling Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    yeah I think so, so what next?

    • 2 years ago
  16. satellite73 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    now that you have \(x=3\) you can replace \(x\) by 3 in either equation to solve for \(y\)

    • 2 years ago
  17. satellite73 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    for example we know \(y=-3x+10\) and we know \(x=3\) making \(y=-3\times 3+10=-9+10=1\)

    • 2 years ago
  18. MeganDarling Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    okay haha, I think I get that too x.x

    • 2 years ago
  19. satellite73 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    solving by graphing is too much work, and besides, if the answer is \((-\frac{1}{7}, \frac{5}{7})\) for example you will never know it from the graph

    • 2 years ago
  20. MeganDarling Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    I know I really hate it too :/ Then again I hate all math. But it's what they are making us do so .

    • 2 years ago
  21. satellite73 Group Title
    Best Response
    You've already chosen the best response.
    Medals 1

    yes, sometimes math (especially this kind) is hateful that is why they invented computers for example, here is the answer to the first one http://www.wolframalpha.com/input/?i=+3y%3D4x%2B7+%2C+-4x-4y%3D28

    • 2 years ago
  22. MeganDarling Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    oh wow that's really cool! Thanks alot.

    • 2 years 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.