Explanation:
y = -x/2 - 1
the y-intercept is right there : -1.
it is the y-value when x = 0
the point of y-intercept is therefore (0, -1).
the x-intercept is the other way around. it is the x- value when y = 0.
0 = -x/2 - 1
1 = -x/2
-2 = x
the point of x-intercept is therefore (-2, 0)