I will gladly simplify it.
9k - 6k + 7k - 8
9k - 6k = 3 k
3k + 7k - 8
3k + 7k= 10k
10k - 8 = 2k
So the simplified form of 9k - 6k + 7k - 8 is 2k
~*"AUBA14"*~