A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

Three-fourths of seven less than a number is forty-two. Find the number.

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

    my ans is -147/4

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

    (3/4)(x-7) = 42. Gogogo

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

    \[\frac{3(x-7)}{4} = 42 \rightarrow \frac{4(42)}{3} = x-7 \rightarrow x=?\]

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

    so the number is 49?

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

    Close.. \[ x-7 = 56 \rightarrow x-7+7 = 56 +7 = x = ?\]

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

    63?

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

    Indeed.

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

    ok i got another for you...i like your help

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

    The real trick here is in setting up the problem initially. Being able to convert word problems into workable equations is a good talent to develop.

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

    suzette did twice as many pushups as mark did. bonnie did five less pushups than mark did. if they did 71 pushups together how many did each do?

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

    \[\text{Polpak I prefer } \implies\ \text{instead of} \rightarrow\] The latter looks to much like a limit.

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

    Let S be the number of pushups Suzette did, and M be the number Mark did, and B is the number Bonnie did. Translate this sentence into an equation. "They did 71 pushups altogether."

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

    Newton: \[ \lim_{n \rightarrow 0}\] Looks like a limit \[ \rightarrow \] doesn't. Not to me anyway. And in my homework I always use a single arrow instead of the double thing, so it feels more natural to me.

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

    \[2s +m=5-m=71 ?\]

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

    That's a bit of a leap. Try just using the variables I defined. If they all did 71 pushups then: \[ M + S + B = 71\]

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

    Then we look at how M, S, and B are otherwise related.

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

    "Bonnie did 5 less pushups then Mark" \[ \rightarrow B = M-5\]

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

    "Suzzette did twice as many pushups as mark" \[ \rightarrow ?\]

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

    2(m)=s

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

    Right. Now, using what we know about S and B, we can go back to our original equation and find how many mark did. \[ M+S+B=71\] Using the fact that S=2M \[ \rightarrow M + 2M + B = 71\] Using the fact that B=M-5 \[ \rightarrow ?\]

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

    im lost

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

    I plugged in 2M for S in the M + S + B = 71 equation. Now do the same for B.

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

    m-5=b

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

    Yes, that's the equation for what B _is_. Now use that in the equation M + S + B = 71

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

    im so confused

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

    B = M - 5. Would you agree then that M + S + B = M + S + (M-5) ?

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

    ok

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

    And since S = 2M Would you agree that M + S + (M-5) = M + 2M + M - 5 ?

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

    i think

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

    \[ S = 2M \] \[\rightarrow M + S = M + 2M \] \[ B = M-5\] \[ \rightarrow M + S + B = M + S + (M-5) \] \[ = (M + S) + (M-5) = M + 2M + M-5\]

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

    Does that make sense?

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

    not at all

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

    S = 2M S + 5 = 2M + 5 right?

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

    If S = 2M then S + SOMETHING = 2M + SOMETHING

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

    That is what equals means

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

    I don't understand what you're not understanding. Which part is confusing?

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

    im a retard when it comes to math...i dnt even know where to begin to solve ur problem

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

    Do you understand what S = 2M means? It means that anywhere you have an S, you can replace it with a 2M and it will mean the same thing.

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

    ok i understand that

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

    So if we have an equation M + S + B = 71, we can replace the S with 2M right?

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

    yea

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

    So rewrite the equation by replacing the S. Also replace the B since we know that B = M-5.

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

    M+2(M)=71?

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

    Not quite. M + 2M = 71 is the same as saying M + S is 71. But we know that's not true because M + S + B is 71 and B is not 0. M + 2M + B = 71 is true. But since we know B = M-5 we can replace B in this equation and we get?

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

    M+2M+M-5

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

    Right. Now, since we said that M + S + B = 71 and we said that M + S + B = M + 2M + M - 5 Then we know that M + 2M + M - 5 = 71 So solve for M.

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

    32m 16s 23b

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

    ?

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

    thats not right

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

    \[ M + 2M + M -5 = 71\] \[ \rightarrow 4M -5 = 71 \] \[ \rightarrow 4M = 76 \] \[ \rightarrow M = 76/4 \] \[ \rightarrow M = 19 \]

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

    38 19 14

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

    S = 2M = 2(19) = 38 B = M-5 = 19-5 = 14

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

    the sum of three numbers is -48. the first number is 12 more than the secong number, andthe third number is 20 less than twice the second number. find the three numbers.

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

    Ok. This one you're gonna need to put more of the effort into. First pick variables for each of your 3 numbers (A, B, C?). Then take each sentance and see what it's telling you about your numbers. (Try to write the sentance as an equation)

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

    The first sentance is: The sum of the three numbers is -48. So your equation is ?

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

    a+b+c=-48

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

    Perfect. Now the next sentence. The first number is 12 more than the second. Therefore?

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

    A=12+B

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

    And finally, The third number is 20 less than twice the second number.

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

    C=20-2(b)

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

    Not quite.

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

    2B = twice the second number. twenty less than twice the second number = twenty less than 2B = 2B - 20 If 2B is 10, than 20 - 10 is not twenty less than 10.

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

    20-2(b)=C

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

    No.

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

    C = 2B - 20

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

    ok

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

    ?

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

    So now put them all together. You have 1 equation with all 3 elements, and 2 other equations that give you replacement values for A and C. So replace them in and solve for B.

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

    once again im lost

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

    A + B + C = -48 A = 12 + B So.. ? + B + C = -48 Fill in the ?

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

    36

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

    ... No A = 12 + B. So (A) + B + C = (12+B) + B + C right??

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

    ya

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

    If A + B + C = -48 and A = 12 + B and C = 2B - 20 the (A) + B + (C) = ?

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

    Just replace the A and the C.

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

    with what?

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

    With what they equal.

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

    i cant tell you what a equals without knowing b

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

    ............... You do know what A equals. A equals 12 + B. Period. It may also be represented in a different way, but you at least know that much.

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

    So put 12 + B where there is an A. And put 2B-20 where there is a C.

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

    12+b+2b-20

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

    Right. And what does that equal again?

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

    =-48

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

    So what does B equal ?

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

    Actually that's not quite right.

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

    -8

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

    you have 12 + B + 2B - 20 which equals (12+B) + (2B-20) which equals A + C. You forgot the B in the middle.

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

    Rewrite the equation again. A + B + C = -48, A = B + 12, C = 2B-20 So...

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

    idk man

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

    im dying here

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

    A + B + C = (12+B) + B + (2B-20) ^A + ^B + ^C Right?

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

    yea

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

    So if A + B + C = -48, what is B.

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

    -36

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

    \[12 + B + B + 2B - 20 = -48\] \[\rightarrow 4B - 20 + 12 -12 + 20 = -48 - 12 + 20 \] \[\rightarrow 4B = -60 + 20\] \[\rightarrow 4B = -40\] \[\rightarrow B = -10\] \[\rightarrow A = 12 + B = 12 + -10 = 2 \] \[\rightarrow C = 2B-20 = -20 -20 = -40 \]

  96. 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.