Results 1 to 3 of 3

Thread: Solving Quadratic Equations/ factoring

  1. #1
    Newbie
    Joined
    Dec 2009
    Posts
    6

    Exclamation Solving Quadratic Equations/ factoring

    Please help, I'm in trig and we are reviewing algebra, having a hard time remembering how to do some of this stuff. Thank you!

    Factor Completely if possible:

    8.) me + mi + my

    Solve each equation for x:

    48.) (2x-3)(2x-3) = 4

    52.) a.) 12x^2 - 5x -3 = 0
    b.) 30x^2 + 13x -10 = 0
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,237
    Thanks
    33
    Quote Originally Posted by iDrum View Post

    Factor Completely if possible:

    8.) me + mi + my
    Take out $\displaystyle m$ as a common factor

    Spoiler:
    $\displaystyle m(e + i + y)$



    Quote Originally Posted by iDrum View Post

    Solve each equation for x:

    48.) (2x-3)(2x-3) = 4

    52.) a.) 12x^2 - 5x -3 = 0
    b.) 30x^2 + 13x -10 = 0

    Exapnd the first equation to find the form $\displaystyle ax^2+bx+c=0$

    Then for that and the other 2 use

    $\displaystyle
    x= \frac{-b\pm\sqrt{b^2-4ac}}{2a}
    $
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    Grandad's Avatar
    Joined
    Dec 2008
    From
    South Coast of England
    Posts
    2,570
    Thanks
    1
    Hello iDrum
    Quote Originally Posted by iDrum View Post
    ...
    Solve each equation for x:

    48.) (2x-3)(2x-3) = 4
    Write this as:
    $\displaystyle (2x-3)^2=4$
    and then take square roots, not forgetting the $\displaystyle \pm$ sign on the right:
    $\displaystyle 2x-3=\pm2$

    $\displaystyle \Rightarrow 2x = 3+2$ or $\displaystyle 3-2$

    $\displaystyle \Rightarrow x = 2.5$ or $\displaystyle 0.5$
    52.) a.) 12x^2 - 5x -3 = 0
    $\displaystyle 12x^2 - 5x -3 = 0$

    $\displaystyle \Rightarrow(3x+1)(4x-3)=0$

    Can you complete it?
    b.) 30x^2 + 13x -10 = 0
    This won't factorise, so use the formula:
    $\displaystyle x=\frac{-13\pm\sqrt{13^2-4(30)(-10)}}{60}$
    Can you complete it?

    Grandad
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: Jul 29th 2011, 12:08 PM
  2. solving quadratic relation by factoring
    Posted in the Math Topics Forum
    Replies: 4
    Last Post: Jul 20th 2008, 03:38 PM
  3. Solving Quadratic Equations by Factoring
    Posted in the Algebra Forum
    Replies: 5
    Last Post: Apr 29th 2008, 01:18 AM
  4. Solving quadratic equations by factoring
    Posted in the Algebra Forum
    Replies: 4
    Last Post: Dec 29th 2007, 06:02 AM
  5. Solving quadratic equations by factoring
    Posted in the Algebra Forum
    Replies: 1
    Last Post: Jan 10th 2007, 10:17 AM

Search Tags


/mathhelpforum @mathhelpforum