Answer:

Step-by-step explanation:
The given sequence is
-12,-16,-20...
The first term of this sequence is
.
The common difference is


The nth term of this arithmetic sequence is;

We substitute the values for the first term and the common difference to obtain;

Answer:
2i and -2i
Step-by-step explanation:
I'll change u to x to be easier to understand.
x^2 = -4
sqrt(x^2) = sqrt(-4)
sqrt(-4) = 2i, or -2i
In an hour, 80 people could ride the ferris wheel. So, that means in 3 hours 240 people could ride it.