The third one, not sure about any other ones.
Consider such events:
A - slip with number 3 is chosen;
B - the sum of numbers is 4.
You have to count 
Use formula for conditional probability:

1. The event
consists in selecting two slips, first is 3 and second should be 1, because the sum is 4. The number of favorable outcomes is exactly 1 and the number of all possible outcomes is 5·4=20 (you have 5 ways to select 1st slip and 4 ways to select 2nd slip). Then the probability of event
is

2. The event
consists in selecting two slips with the sum 4. The number of favorable outcomes is exactly 2 (1st slip 3 and 2nd slip 1 or 1st slip 1 and 2nd slip 3) and the number of all possible outcomes is 5·4=20 (you have 5 ways to select 1st slip and 4 ways to select 2nd slip). Then the probability of event
is

3. Then

Answer: 
Answer:
r = 2
Step-by-step explanation:
slope = (y2 - y1)/(x2 - x1)
(-1, -5)
(r, -9)
-5 - (-9) / -1 - r = 2
4 / -1 - r = 2
r = -2
-1 - (-3) = 2
4 / 2 = 2
Please let me know if I've gotten anything wrong!
Step-by-step explanation:
f(a+h) – f(a)/h = –3
so the answer is –3