we are given
airthematic sequence
we can use nth term formula
n is number of terms
an is nth term
d is common difference
a1 is first term
We are given
a7=40
we can use it
a18 = 106
we can subtract both equations
now, we can find a1
we can plug d=6
12th term:
now, we can plug values
so, 12th term is 70...........Answer
Answer:
Step-by-step explanation:
<u>Exponential Growth </u>
The natural growth of some magnitudes can be modeled by the equation:
Where P is the actual amount of the magnitude, Po is its initial amount, r is the growth rate and t is the time.
The initial number of bacteria is Po=40 and it doubles (P=2Po) at t=20 min. With that point we can find the value of r:
Simplifying:
Solving for 1+r:
The exponential function that models the situation is: