there is no way to solve that, 108k+ 120 is just 108k +120 you can factor out a 12 so it becomes:
12(9k + 10)
thats about all you can do unless it equals something or its like terms such as 108k + 120k or 108k + 120 = 0 , there isnt any way to solve it aside from factoring out the 12.