find all numbers for which the rational expression is undefined (1/w-6)

Answer 1

I think it'd be just 6, I'm pretty sure..sort of.

Answer 2

The expression 1/w - 6 is undefined if its value is zero.

1/w - 6 = 0
1/w = 6
w = 1/6

so the expression is undefined if w = 1/6