Question 988218
3x+4=12x+5

This is what I"ve tried but don't know if I'm right. Plus I need to know how to check my work.

3x+4=12x+5  I saw somewhere that I make the 4 a -  why do I make it a negative?
then add 4 to both sides
3x=12x+9   then divide all by 3
x=4x+3   
Where do I go from here and please show me how to check my work. Thank you and God bless. 
<pre>  3x + 4 = 12x + 5
      3x = 12x + 1 --- Subtracting 4 from both sides in order to ISOLATE 3x
3x - 12x = 1 --------- Subtracting 12x from both sides to isolate x
    - 9x = 1
      {{{x = 1/(- 9)}}} --------> {{{highlight_green(x = - 1/9)}}}

<pre>
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Check
======</pre>Since {{{x = - 1/9}}}, substitute this value into the original equation
Therefore, 3x + 4 = 12x + 5 becomes:
{{{3(- 1/9) + 4 = 12(- 1/9) + 5}}}
{{{cross(3)(- 1/3cross(9)) + 4 = 4cross(12)(- 1/3cross(9)) + 5}}}
{{{- 1/3 + 4 = - 4/3 + 5}}}
{{{3&2/3 = - 1&1/3 + 5}}} 
{{{3&2/3 = 3&2/3}}} (TRUE)