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

Homework Help: Have I done the quadratic equation correctly?

  1. Mar 5, 2010 #1
    x2 + 3x + 2 = 0

    (x + 1) (x + 2)

    so x = -1 or -2

    Is that right?
     
  2. jcsd
  3. Mar 5, 2010 #2

    Mentallic

    User Avatar
    Homework Helper

    Yes. You can check if you factorized correctly by expanding your factors out.
    or... you can check if your answers are correct by substituting them into the quadratic.

    If the left-hand side is equal to the right-hand side, then you've found the correct values for x.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook