4x + 12 = 3(4 - X)

well 4x + 12 = 12 - 3x

4x + 12 -12 =12 - 3x -12

= 4x -12 = 12 -12 -9

= -8x -9

=8x/8 -9/8 = - 1 1/8 book says answer is 0 . not thinking right can someone help.

Printable View

- Jan 27th 2009, 10:06 AMLeona_Mariewhats the right answer
4x + 12 = 3(4 - X)

well 4x + 12 = 12 - 3x

4x + 12 -12 =12 - 3x -12

= 4x -12 = 12 -12 -9

= -8x -9

=8x/8 -9/8 = - 1 1/8 book says answer is 0 . not thinking right can someone help. - Jan 27th 2009, 10:10 AMChris L T521
- Jan 27th 2009, 10:39 AMLeona_Marie
switching 12 around doesnt make the answer 0

4x +12 -12 = -3x + 12 -12

= 4x = -3x

=4x +3x = -3x + 3x

=7x not 0 plus the only rule is that whatever you do to the left you have to do to the right. the right in this equation is -3x so -3x -12, which is 3x -12 ,would be -9 - Jan 27th 2009, 12:33 PMmasters
Go back and look at what Chris has shown you.

$\displaystyle 4x+12-12=12-3x-12\implies 4x+(12-12)=-3x+(12-12)$

$\displaystyle 4x+0=-3x+0$

$\displaystyle 4x=-3x$

$\displaystyle 4x+3x=0$

$\displaystyle 7x=0$

$\displaystyle x=0$ - Jan 27th 2009, 03:13 PMLeona_Marie
masters , please explain to me how 7x = 0 or x = 0 the only thing I would know how to do is to devide 7x/7 0/7 = 0 ? plus Ive never seen wher you can swap + -3x + 12 or visa versa is this the case or am I missing something again. in other words the question was written out12 -3x so shouldnt the number come off the right. I think I just got it please verify.

- Jan 27th 2009, 05:28 PMTheMasterMind
- Jan 27th 2009, 05:32 PMTheMasterMind