Question

The table shows the predicted growth of particular bacterium after various numbers of hours. Write an explicit formula for the sequence of the number of bacterium.
What is the 12th term of the sequence 15, 11, 7, …?

Answer 1

Answer:

D

-29

Step-by-step explanation:

Problem 1

In the first hour, the number of bacteria is 22

In the second hour,the number of bacteria is 44

It looks like the formula is some multiple of 22

That means you should pick D

Problem 2

n = 12

a = 15

d = - 4

an= 15 + (n - 1)*d

a12 = 15 + 11*(-4)

a12 = 15 - 44

a12 = - 29