Answer:
y = -x - 1
Explanation:
The formula for linear equations is
y=mx+b
with m being your slope which is just your rise/run (up/down and right/left)
and b being your y-intercept (where the line touches the vertical line)
Your y intercept is -1
y=mx-1
your slope is -1
1/1 = 1
it goes up down 1 and down to the left 1
so it will be negative
-1
y = -1x - 1
or
y = -x - 1