Question

6-1/3x=-1 How do I do this

Answer 1

Im gonna assume you mean 6 - (1/3)x = -1.  Your notation is not super clear.  If so, solution is as follows:

6 - (1/3)x = -1   [subtract 6 from both sides]
-(1/3)x = -7       [multiply both sides by -3]
x = 21