Writing and interpreting exponential functions

The equation y = 210(1.094)^x depicts the amount of money in a savings account after x years. What does the y-intercept represent in the equation?

The function $$b\left(t\right)=8000\cdot0.98^t$$ represents the number of bacteria in a petri dish as a function of time. The way to find the rate is to subtract ​ (a)   -​ (b)   . Then move the decimal over ​ (c)   spaces to the ​ (d)   to create a percent.

What is the starting amount in the problem

$$f\left(x\right)=300\left(1.05\right)^x$$  

What is the starting amount in the problem below?

f(t) = 300(1.05)^t

We have an initial investment growing at 8%.

Match each part of the equation with it's meaning.

$$A\left(t\right)=1,000\left(2\right)^{\frac{t}{9}}$$

A store manager adjusts the price of an item each week that the item goes unsold. The price of the unsold item, in dollars, after x weeks can be modeled by the exponential function $$f\left(x\right)=320\left(0.90\right)^x.$$ Select ONE correct answer in each box to complete each sentence. The initial price of the item before the store manager made any adjustments was ​ ​ (a)  

The price of the item ​ (b)   at a rate of ​ (c)   each week.

Two students were infected by chicken pox today. The number of infected students are a function of the number of days, x. The number of infected students, after each day, x, is given by the function A(x) = 2(3)^x. What does A(6) = 1,458 mean in the context of the problem?

 $y=-1.5\left(3\right)^x$  What's the y-intercept of the function?

What does the y-intercept represent in the word problem?

Q = 3.1(0.78)^t

What is the initial quantity?

(a)