Results 1 to 3 of 3

Math Help - solving radical equations

  1. #1
    Newbie
    Joined
    Sep 2009
    Posts
    7

    solving radical equations

    directions say to find all solutions

    1. (x + 4)^1\2 + 5x(x + 4)^3/2 = 0

    I don't know how to get rid of the fractions when there are two of them
    any help appreciated
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    12,110
    Thanks
    986
    Quote Originally Posted by isundae View Post
    directions say to find all solutions

    1. (x + 4)^1\2 + 5x(x + 4)^3/2 = 0

    I don't know how to get rid of the fractions when there are two of them
    any help appreciated
    (x+4)^{1/2} + 5x(x+4)^{3/2} = 0

    factor ...

    (x+4)^{1/2}[1 + 5x(x+4)] = 0

    (x+4)^{1/2}(5x^2 + 20x + 1) = 0

    set each factor equal to 0 and solve ...

    x = -4

    x = \frac{-10 \pm \sqrt{95}}{5}
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member pacman's Avatar
    Joined
    Jul 2009
    Posts
    448
    (x + 4)^(1/2) + 5x(x + 4)^(1+1/2) = 0, by factoring (x + 4)^(1/2).

    (x + 4)^(1/2)(1 + (5x)(x + 4)) = 0,

    (x + 4)^(1/2)(1 + 20x + 5x^2) = 0

    THESE are the 3 roots:
    x_1 = -4,
    x_2 = -2 - sqrt (19/5) = -3.95
    x_3 = sqrt (19/5) - 2 = -0.05

    see graph,
    Attached Thumbnails Attached Thumbnails solving radical equations-awer.gif   solving radical equations-awer-2.gif  
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Solving Radical equations
    Posted in the Algebra Forum
    Replies: 1
    Last Post: March 14th 2010, 07:22 PM
  2. Solving radical equations
    Posted in the Algebra Forum
    Replies: 1
    Last Post: November 12th 2009, 04:58 PM
  3. Solving Radical Equations
    Posted in the Algebra Forum
    Replies: 1
    Last Post: April 18th 2009, 08:04 AM
  4. Solving Radical expressions
    Posted in the Algebra Forum
    Replies: 1
    Last Post: February 18th 2009, 10:35 PM
  5. Solving radical equations
    Posted in the Algebra Forum
    Replies: 1
    Last Post: October 15th 2008, 03:16 PM

Search Tags


/mathhelpforum @mathhelpforum