A y-intercept is the value at which x = 0.
(4,0) is not a y-intercept because x = 4.
(-1, 1) is not a y-intercept because x = -1.
(0,0) is a y-intercept because x = 0.
(0, -7) is a y-intercept because x = 0.
(-2, 2) is not a y-intercept because x = -2.
(0, -0.25 is a y-intercept because x = 0.
