Ok guys... this is my last question and I have been on it for about 15 minutes, and I need help... I can't tell whether the answer is going to be -1/6-1/6 or a/6-1/6 or 1-1/6.... help me please ASAP <3

Ok guys this is my last question and I have been on it for about 15 minutes and I need help I cant tell whether the answer is going to be 1616 or a616 or 116 he class=