Need help w/ an absolute value problem where a no. is placed outside the equation within the absolute value signs-what should I do first?

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- Sep 5th 2008, 12:54 PMTNBAbsolute Value Equations
Need help w/ an absolute value problem where a no. is placed outside the equation within the absolute value signs-what should I do first?

- Sep 5th 2008, 01:10 PMJhevon
since you chose to be vague, the most i can tell you is that

$\displaystyle |x| = \sqrt{x^2} = \left \{ \begin{array}{lr} x & \mbox{ if } x \ge 0 \\ & \\ -x & \mbox{ if } x < 0 \end{array} \right.$

so you need to split your equation in two to account for the possible change in sign of what's in absolute values.

example. $\displaystyle |3x - 1| = 2$

$\displaystyle \Rightarrow 3x - 1 = 2 \mbox{ or } -(3x - 1) = 2$

and continue - Sep 5th 2008, 01:17 PMTNB
It's like your final ex, save there's a number attached to the back end.

somthing like this...... 7 http://www.mathhelpforum.com/math-he...fe8dc286-1.gif

Sorry about the lack of detail. Just trying to speed things up.. Typing wise, anyhow. - Sep 5th 2008, 01:20 PMJhevon
- Sep 5th 2008, 01:23 PMILoveMaths07Absolute value
In that case, do NOT multiply the 7 with the expression 3x - 1. That'll change the absolute value! Instead, divide 7 on both sides, and then proceed.

|3x - 1| = 2/7

Now proceed...

I hope that helps. :)

ILoveMaths07.

P.S. THIS IS MY FIRST POST!!! (Hi) - Sep 5th 2008, 01:24 PMJhevon
- Sep 5th 2008, 01:39 PMTNBThank you Jhevon.
Much thanks. Couldn't really remember whether to subtract or divide.....

- Sep 5th 2008, 01:45 PMILoveMaths07
You can't subtract because it's $\displaystyle 7 * |3x - 1| $. You must divide the 7 on both sides.