Answer :
Step 1 u want to subtract 4 from both sides 3x+4-4=12-4
3x=8
Step 2 divide 3 from both sides
3x. 8
----= ---
3. 3
x=8/3
3x=8
Step 2 divide 3 from both sides
3x. 8
----= ---
3. 3
x=8/3