Ok so I have a utility function of

U = x1x2

It asks how do I write an equation for the indifference curve for (6,1)

I have spent 2 hours on this, I know its easy, I honestly cannot remeber anything about equations of lines or the sort. I am thinking that if u=6. Then prehaps it would just be

x=1/6

I really don't know. there is no examples on how to do this I think it assumes I know how to equate curves.