Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How to solve for x?

  1. Feb 13, 2005 #1
    How do I solve for x in the following question? I'm pretty sure you have to factor, but how do I solve for x with two x variables?

    4x^2 + x = 0
  2. jcsd
  3. Feb 13, 2005 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    'x' is a common factor to both terms. Factor it out:

    x(4x + 1) = 0

    Do you know how to solve it now?
  4. Feb 13, 2005 #3
    Ummm Im not too sure :grumpy:
  5. Feb 13, 2005 #4
    4x^2 + x = 0
    from there, you can take out the x.
    so.. x(4x+1)=0 since (that is equilivent to 4x^2 + x = 0 )
    so now, you have (x) times (4x+1) equals 0, what do either have to be in order for the equation to equal 0?
    so you have x=0 and 4x+1=0
    you solve for x, and you get 0,-1/4
  6. Feb 13, 2005 #5


    User Avatar

    0 or -0.25 via the "quadratic formula".
  7. Feb 13, 2005 #6
    EDIT: Yup I figured it out before I refreshed the page lol. Thanks guys.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook