The answer you are looking for is K = -5/6.
To find this, you must get K by itself. First, subtract 8k from both sides to get 12k + 11 = 1. Next, subtract 11 from both sides to get 12k = -10. Finally, divide both sides by 12 to get K = -10/12, which simplified, is -5/6. Thus making -5/6 the answer.
I hope this helps!