Q&A #1530

Teachers' Lounge Discussion: Factoring out -1 in algebraic expressions

T2T || FAQ || Ask T2T || Teachers' Lounge || Browse || Search || T2T Associates || About T2T

View entire discussion
[<< prev] [ next >>]

From: Teresa

To: Teacher2Teacher Public Discussion
Date: 2003040912:16:57
Subject: Re: x squared minus one divided by one minus x


Factor the top to (x+1)(x-1), a difference of squares. Next
multiply the bottom by -1 to change the signs. Now we have
cancel the (x-1)s. Now we have x+1/-1.
Now flip and multiply. x+1 times -1. 

Because the -1 is on the bottom it is actually 1/-1. When you flip
this to multiply you have the correct answer.
Hope this is helpful.

Post a reply to this message
Post a related public discussion message
Ask Teacher2Teacher a new question

[Privacy Policy] [Terms of Use]

Math Forum Home || The Math Library || Quick Reference || Math Forum Search

Teacher2Teacher - T2T ®
© 1994- The Math Forum at NCTM. All rights reserved.