Answer:
5
Step-by-step explanation:
A fair coin just means 50% heads 50% tails. so the sample is still 50% heads 50% tails.
8minutes-2minutes=6minutes
6×80 copies = 480 copies
Answer:
a difference of squares
Step-by-step explanation:
Let's write down the expression:

we can see that this expression is one of the form
which is the general expression of a difference of squares.
To be more specific and to see why we say this, let's make
and 
Now, if we substitute this in the general formula, we get:

Thus, this expression is a difference of squares.