Results 1 to 2 of 2

Math Help - polynomial equation- Algebra 2 help

  1. #1
    Newbie
    Joined
    Apr 2007
    Posts
    6

    polynomial equation- Algebra 2 help

    a rectangular garden is 10ft wide and 12ft long. a walk of uniform width surrounds the garden. if the total area of the garden and the walk is 168ft squared , what is the width of the walk?

    can you help... I don't understand the problem, I can do the work but I end up with negatve answers.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    is up to his old tricks again! Jhevon's Avatar
    Joined
    Feb 2007
    From
    New York, USA
    Posts
    11,663
    Thanks
    3
    Quote Originally Posted by pieman396 View Post
    a rectangular garden is 10ft wide and 12ft long. a walk of uniform width surrounds the garden. if the total area of the garden and the walk is 168ft squared , what is the width of the walk?

    can you help... I don't understand the problem, I can do the work but I end up with negatve answers.
    Let's see here


    let the width of the walk be x. since the walk surrounds the garden, the width of the garden is going to be it's width + 2x and the length of the garden is going to be it's length + 2x.

    now just plug these values into the area equation:

    we have length = 12 + 2x
    we have width = 10 + 2x
    area = length*width

    => area = 168 = (12 + 2x)(10 + 2x)

    => (12 + 2x)(10 + 2x) = 168
    => 120 + 44x + 4x^2 = 168 ............i expanded the brackets
    => 30 + 11x + x^2 = 42 .................i divided through by 4
    => x^2 + 11x - 12 = 0
    => (x + 12)(x - 1) = 0
    => x + 12 = 0, or x - 1 = 0
    => x = -12 or x = 1

    x cannot be minus 12, since it's a length
    so x = 1 ft

    so the width of the walk is 1 ft
    Last edited by Jhevon; April 19th 2007 at 05:29 PM.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. algebra, a root of polynomial
    Posted in the Advanced Algebra Forum
    Replies: 11
    Last Post: May 4th 2008, 09:01 AM
  2. polynomial algebra
    Posted in the Algebra Forum
    Replies: 1
    Last Post: May 4th 2008, 07:25 AM
  3. Algebra polynomial
    Posted in the Algebra Forum
    Replies: 2
    Last Post: June 12th 2007, 05:57 PM
  4. Polynomial Algebra
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: April 14th 2007, 05:59 PM
  5. algebra polynomial help
    Posted in the Algebra Forum
    Replies: 6
    Last Post: March 8th 2007, 07:40 AM

Search Tags


/mathhelpforum @mathhelpforum