First things first, lets distribute. On the left side, you multiply the c-4 by 3, which comes out to 3c-12. On the right side, multiply everything inside the parenthesis by 4, which makes it 4c-24. So now you have 3c-12=4c-24. Now to simplify. We always stare with the numbers farthest away from the exponent, which in this case is -12 and -24. When simplifying, we always want to make it a positive number if possible to keep it easy. now, we add 24 to both sides (to cancel out the -24) which gives us 3c+12=4c. After that, we subtract 3c to both sides, which gives us 12=c, or c=12. Hope that helps!
