You are trying to find the value of K, so to do that you need to get k by itself (example : K= 3-5 instead of K+5= 3)
So in 1a i would simplify 7k-3k= 4k
then 4k=11
now to get rid of the 4 and get the k alone- you DIVIDE 4k by 4 and divide 11 by 4 cause you need to do it on both sides of the equation, it should look like this.