Answer:
a: undefined
b: -15
c: 20
d: 25
Explanation:
a: look at x -3 on graph, the left hand limit and right hand limits are different so it's undefined
b: look at x 0 on graph, there is open dot at -15 meaning the limit is there
c: look at x -7 on graph, there is open dot at 20 meaning the limit is there
d: look at x 5 on graph, the y is at 25 meaning the limit is there (it's normal here)