I am so very confused, answers please.

Define multiplicative inverse. give an example of a number and its multiplicative inverse.

F. a fair coin is thrown in the air four times. if the coin lands with the head up on the first three tosses, what is the probability that the coin will land with the head up on the fourth toss? a. 0 b. 1/16 c. 1/8 d. 1/2

What is the slope of the line? a. -5/2 b.2/5 c. 5/2 d.7/2