A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 4 years ago

a/a+4=3-4 marian can weed a garden in 3 hrs. robinm can weed the same garden in 4 hrs. how longh will the weeding take them if they work together? 3/m-1=2m/m+4- solve this equation check solution if there is no solution put no solution Help Please!!

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

    a/a+4=3-4/a+4

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

    |dw:1330229793561:dw|

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

    would you move everything with an a on one side

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

    The weeding problem is solved by just taking the product divided by the sum (3 X 4)/7=12/7 hr or 1 5/7 hour.

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

    Multiply all terms by (a+4) getting a = 3(a+4)-4 a = 3a +12 -4 -2a=8 a=-4

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

    huh?? alll ternmss

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

    To check (-4)/(-4+4) can't go any further as division by 0 is not permitted. Let me check my work. Are you sure you have it copied correctly?

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

    The equation is not valid as denominator results in 0

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

    yes i did

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

    soo no solution

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

    |dw:1328675059499:dw||dw:1328675072118:dw| The equation has 3 terms.

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

    |dw:1330230347158:dw|

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

    No solition.

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

    i get it now next problem do we multiply by m?

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

    dessyk, have you ever heard of cross multiplying? We could do that.

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

    ohh yeaa

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

    3m+12=2m^2-2m

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

    3(m+4)=2m(m-1) 3m + 12 =2m^2 -2m Yes you got now consolidate and simplify \[2m ^{2}-5m-12=0\]

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

    then the quadratic equation?

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

    Factor getting (m-4)(2m+3) m=4 m=-3/2 those are the two solutions.

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

    Yes it is a quadratic, but a easily factored one lol

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

    i see it next problem

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

    I will leave the proof up to you.

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

    |dw:1330230943000:dw|

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

    Is the last term d+6 over d^2-4?

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

    yess

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

    we would mulktiply by d

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

    And are you sure that the denominator of the 2nd term is 2-d or is it d-2 ??

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

    its 2-d

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

    O.K First I am going to change the 2nd terms appearance, but not its value by multiplying it by -1 and again by-1 (which is 1) so the equation will now look like this:|dw:1328676105960:dw|

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

    Note that (d^2-4) is (d+2)(d-2) Now multiply all terms by (d^2-4) getting \[d ^{2}-2d +2d+4 = d\]No tricks here everything legal lol

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

    Simply: \[d ^{2}-2d+2d+4=d+6 \]ooops I made a mistake I dropped of that 6 so it is now.

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

    \[d ^{2}-d-2=0\]can be factored (d-2)(d+1) d=2 d=-1 Proof left up to you.

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

    |dw:1328676821005:dw|

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

    two pipes fill a storage tank in 9 hrs. the larger pipe fills the tank 3 times as fast as the smaller one . How long would it take the larger pipe to fill the tank alone?

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

    d=2 is not a valid solution as it would result in zero in the second term,so d=-1

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

    so its one solution

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

    Yes

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

    Can not divide by 0.

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

    next problem and last

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

    two pipes fill a storage tank in 9 hrs. the larger pipe fills the tank 3 times as fast as the smaller one . How long would it take the larger pipe to fill the tank alone?

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

    hello??

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

    First you know the larger pipe will fill it quicker than the smaller one. let x time to fill with larger pipe then 3x is the time to fill with smaller pipe. Use product over sum to solve this type problem especially when you only have two things working. 3x * x =3x^2 3x + x =4x product over sum is:\[3x ^{2}\over4x\] and this equals 9 (given) solve by cross multiplying: 36x=3x^2 or \[3x ^{2}-36x=0\]factoring getting: 3x(x-12)=0 x=12 large pipe will fill it in 12 hours, small pipe will take 36 hours,together 9 hours.

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

    Thats all for me tonight. Be sure and double check answers by proofing.

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

    That way if I goofed you will be able to correct my mistake.

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

    thnk u sooooo much youve really helped meee

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

    ur welcome, I was just looking at that last one and it would be simpler to just reduce that 3x^2/4x to 3x/4 and set that to =9 3x/4 =9 getting 3x =36, x=12 (no quadratic that way lol)

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

    Good night and good luck in your studies.

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

    thnks

  50. 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.