Find a recursive rule that models the exponential decay of y=1600(0.97)^t

The exponential models describe the population of the indicated country, A, in millions, t years after 2010.Which country has the greatest growth rate? By what percentage is the population of that country increasing each year?
India, $A=1173.1e^{0.008t}$
Iraq, $A=31.5e^{0.019t}$
Japan, $A=127.3e^{0.006t}$
Russia, $A=141.9e^{0.005t}$

The population of California was 29.76 million in 1990 and 33.87 million in 2000. Assume that the population grows exponentially.
(a) Find a function that models the population t years after 1990.
(b) Find the time required for the population to double.
(c) Use the function from part (a) to predict the population of California in the year 2010. Look up California’s actual population in 2010, and compare.

Is the sum of two complex numbers always a real number?

Biff observes that in every math test he has taken this year, he has scored 2 points higher than the previous test. His score on the first test was 56. He models his test scores with the exponential function ${\displaystyle s\left(n\right)=28\cdot 2^n}$ where s(n) is the score on his nth test. Is this a reasonable model? Explain.

Whether the given function is an appropriate model for extended years and explain the reason.
Given: The polynomial function is ${\displaystyle f\left(x\right)=-0.87x^3+0.35x^2+81.62x+7684.94}$
Here, x represents the number of years after 1987 and f(x) represents the number of thefts in that respective year.

To calculate: The coefficient and the degree of each term of the polynomial ${\displaystyle 8-x^2{y}^4+y^7}$ and then find the degree of the polynomial.

What is the product of 109 and 276?