so you trying to get C by itself right? first:
1: subtract 11 from both sides so you end up with 0 on one side an the factors on the left side. when you do this you should get: 0=c/-5-3.
2: find the least common denominator in both the fractions.
3: perform your operation and then multiply it by its reciprocal (leave out the c). REMEMBER that what you do to one side you also do to the other. whats you multiply by the reciprocal and do your canceling on the right side you will have isolated your variable (C).