Answer:
A. add 81; 
Step-by-step explanation:
The perfect square formula
Rewrite expression 
as follows:
So, to form a perfect square, 
is missed.
When we add 
we will get
D. is the answer
random words to fill the 20 word count
Answer:
An event with a probability of 0 is impossible.
An event with a probability of 1 is certain.
Step-by-step explanation:
Probability is typically expressed in terms of a fraction between 0 and 1 where the denominator is the total number of outcomes and the numerator is the number of desired outcomes. Since probability is expressed as a fraction, if the probability is 0, that means it is impossible, or there is no chance that the event can happen. However, if the probability is 1, that means that the event is certain to happen and the odds are completely in your favor that the event will happen.
