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: Pre-calculus; linear inequalities

  1. Sep 14, 2010 #1
    1. The problem statement, all variables and given/known data

    1. 9x^2 + 12x + 4 ≥ 0

    2. 2 - 5x - 3x^2 ≤ 0

    2. Relevant equations

    3. The attempt at a solution

    1. Can't you factor this into (3x + 2) (3x + 2)?
    2. Looking at this inequality, im thinking if you can change this inequality into 3x^2 + 5x + 2.
     
  2. jcsd
  3. Sep 14, 2010 #2

    LCKurtz

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Yes, you can. So what is your conclusion about the x that satisfy it?

    What you have changed it into isn't an inequality and you likely have a sign error. Did you mean to write 3x2 + 5x - 2 ≥ 0? If so, what next?

    Also, your title says linear inequalities. These aren't linear inequalities; they are quadratic inequalities.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook