3x+11=10x-12
We move all terms to the left:
3x+11-(10x-12)=0
We get rid of parentheses
3x-10x+12+11=0
We add all the numbers together, and all the variables
-7x+23=0
We move all terms containing x to the left, all other terms to the right
-7x=-23
x=-23/-7
x=3+2/7