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fiftrombone
07-16-2006, 05:16 PM
if you have like l ax+b l = l cx+d l do you jsut solve it like ax+b = cx+d then solve also for ax+b = -(cx+d)?

daon
07-16-2006, 05:20 PM
if you have like l ax+b l = l cx+d l do you jsut solve it like ax+b = cx+d then solve also for ax+b = -(cx+d)?

You got it!

fiftrombone
07-16-2006, 05:34 PM
thanks a lot.

fiftrombone
07-16-2006, 05:38 PM
wait. that didnt work when i tried to solve my problem. it is the same variable on both sides of the equation. and it is an absolute value on both sides. how do i solve for x?

jonboy
07-16-2006, 05:56 PM
So this is exactly what we are trying to solve for \L x:

\L \left| {ax + b} \right| = \left| {cx + d} \right|

skeeter
07-16-2006, 05:58 PM
|ax + b| = |cx + d|

case 1 ...

ax + b = cx + d
ax - cx = d - b
x(a - c) = d - b
x = (d - b)/(a - c)

case 2 ...

ax + b = -(cx + d)
ax + b = -cx - d
ax + cx = -b - d
x(a + c) = -(b + d)
x = -(b + d)/(a + c)

fiftrombone
07-16-2006, 06:08 PM
ok thank you. i think when i worked my problem through the first time i just dod some math wrong becasue it does work. thank all so much for your help.