Drexel dragonThe Math ForumDonate to the Math Forum


Math Forum
 Ask Dr. Math
 Discussions
 Internet Newsletter
 MathTools
 Problems of the Week
 Teacher2Teacher
 Teacher Exchange
 Workshops

Search All of the Math Forum:
Browse our Internet Mathematics Library

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » sci.math.* » sci.math

Topic: Please help refresh my Algebra skills (factoring & solving)
Replies: 9   Last Post: Oct 18, 1999 10:23 PM

Advanced Search
Reply to this Topic Reply to this Topic

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
dannyboy@here.com

Posts: 682
Registered: 12/6/04
Re: Please help refresh my Algebra skills (factoring & solving)
Posted: Oct 17, 1999 5:50 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply



On Sun, 17 Oct 1999 15:06:40 -0400, "Nick Marques" <nickjm@jnlk.com>
wrote:

>If I have some nasty numbers in quadratic form, how do I factor and solve
>for the TWO answers??
>
>-4.9x^2+5.5x-105=0
>That factors to x(-4.9x+5.5) = -105

Gets you nowhere. You are looking for two factors of the form
(Ax+B)(Cx+D). The + might be -. However, MUCH easier to use the
quadratic formula, especially in this case as you will see.

Start with positive x^2 (why not?)

4.9x^2 - 5.5x + 105 = 0

Use the formula:

x = (-b +-sqrt(b^2-4ac)/2a to get

x = (5.5 +-sqrt((5.5)^2 - 4*4.9*105))/(2*4.9)

Out with the calculator, and it looks like they might be complex
roots.

Dan.

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2015. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.