The y-intercept of the line whose equation is x - y = -1 is -1 0 1

The y-intercept in the equation in the form y = mx + b is b.
To find the y-intercept in x - y = -1, isolate y on the left-hand side:

x - y = -1
-y = -x - 1
y = x + 1

b in this equation is 1, so the y-intercept is 1.

Hope this helps.

The decimal expansion would be .27 repeated