Results 1 to 7 of 7

Math Help - Frustrating word problems

  1. #1
    Newbie
    Joined
    Apr 2008
    Posts
    16

    Frustrating word problems

    Hello, I am new to these forums. After hitting a wall on my take-home quiz, I am on the hunt for some assistance. Our professor told us we can use any means necessary to get help, so I am doing just that! Always been terrible at word problems, algebra in general for that matter. Have two problems here that left me with nothing but a blank paper and a nasty migraine!

    1. The area of a rectangle is 80 meters^2 (squared). The length is six more than twice its width. Find the length and width.


    2. The profit P, generated for a video store is given by the equation p = x^2 - 15x - 50, where X indicates the number of videos sold. How many videos must be sold for the profit to be $200?


    Thanks in advance!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by Fails_at_Math View Post
    Hello, I am new to these forums. After hitting a wall on my take-home quiz, I am on the hunt for some assistance. Our professor told us we can use any means necessary to get help, so I am doing just that! Always been terrible at word problems, algebra in general for that matter. Have two problems here that left me with nothing but a blank paper and a nasty migraine!

    1. The area of a rectangle is 80 meters^2 (squared). The length is six more than twice its width. Find the length and width.


    2. The profit P, generated for a video store is given by the equation p = x^2 - 15x - 50, where X indicates the number of videos sold. How many videos must be sold for the profit to be $200?


    Thanks in advance!
    1. Solve 80 = x(2x + 6) => 2(x - 5)(x + 8) = 0 for x, where x is the width. Keep the answer that makes sense.

    2. Solve 200 = x^2 - 15x - 50 => (x - 25)(x + 10) = 0 for x. Keep the answer for x that makes sense.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Super Member angel.white's Avatar
    Joined
    Oct 2007
    Posts
    723
    Awards
    1
    Quote Originally Posted by Fails_at_Math View Post
    1. The area of a rectangle is 80 meters^2 (squared). The length is six more than twice its width. Find the length and width.
    First you need to write a formula that relates length, width, and area. Fortunately, this is a common formula: A=L*W

    We know A since it is given, so plug that into the formula:

    80 = L*W

    Now we have two variables, but lets get it down to one so that we can actually solve for something. How do length and width relate to eachother? Well we were told that length is 6 more than twice the width, so L = 6+2W

    Now we can substitute this value in for L

    80 = (6+2W)*W

    80 = 6W +2W^2

    40 = W^2 + 3W

    0 = W^2 + 3W - 40

    Solve by factoring (Hint: -40 = -5*8)
    This will give you two solutions (use the positive answer since you can't have negative width).
    Then plug that answer into the equation again and solve for length.
    Quote Originally Posted by Fails_at_Math View Post
    2. The profit P, generated for a video store is given by the equation p = x^2 - 15x - 50, where X indicates the number of videos sold. How many videos must be sold for the profit to be $200?
    p is profit = 200 so plug that in:

    200 = x^2 -15x - 50

    0 = x^2 -15x - 250

    Now you just factor it (hint: -250 = -25 * 10)
    This will give you two solutions, evaluate which makes the most sense (hint: it doesn't make sense to sell negative videos)
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Newbie
    Joined
    Apr 2008
    Posts
    16
    I see now how it relates back to the rest of the problems we have been doing in class. Just hit a wall trying to put the words into equation form, but I guess that's the real challenge of word problems. Thanks MHF!
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Super Member angel.white's Avatar
    Joined
    Oct 2007
    Posts
    723
    Awards
    1
    Quote Originally Posted by Fails_at_Math View Post
    Just hit a wall trying to put the words into equation form, but I guess that's the real challenge of word problems. Thanks MHF!
    For me the real challenge of word problems is that I can't read :/

    I don't even know what the question was, I just copied Mr. Fantastic's answer and changed the variable letters. I don't even know what you just posted, I'm just randomly hitting keys right now, I don't even know what I'm typing!

    Follow Math Help Forum on Facebook and Google+

  6. #6
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by angel.white View Post
    For me the real challenge of word problems is that I can't read :/

    I don't even know what the question was, I just copied Mr. Fantastic's answer and changed the variable letters. I don't even know what you just posted, I'm just randomly hitting keys right now, I don't even know what I'm typing!

    The resemblance is uncanny
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Super Member angel.white's Avatar
    Joined
    Oct 2007
    Posts
    723
    Awards
    1
    Quote Originally Posted by mr fantastic View Post
    The resemblance is uncanny
    Why do you think I wear a hat and sunglasses?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Problems with integration word problems
    Posted in the Calculus Forum
    Replies: 5
    Last Post: April 25th 2010, 06:39 PM
  2. Frustrating Word Problem!
    Posted in the Algebra Forum
    Replies: 2
    Last Post: October 13th 2009, 05:45 PM
  3. Frustrating Hmwk DUE
    Posted in the Trigonometry Forum
    Replies: 2
    Last Post: October 3rd 2008, 05:10 PM
  4. Frustrating integral
    Posted in the Calculus Forum
    Replies: 3
    Last Post: December 3rd 2007, 11:56 PM
  5. Frustrating problem
    Posted in the Geometry Forum
    Replies: 3
    Last Post: June 29th 2007, 08:54 PM

Search Tags


/mathhelpforum @mathhelpforum