We have been given that you invest $850 into a stock market fund, which grows at a rate of approximately 4% each year. We are asked to write an equation that can be used to calculate the amount of money in the fund after x years.
We will use exponential growth formula to solve our given problem.
An exponential function is in form 
, where,
y = Final amount,
a = Initial amount,
r = Growth rate in decimal form,
x = Time.
Let us convert 4% into decimal.
.
We have 
and 
, so our equation would be:
Therefore, the equation can be used to calculate the amount of money in the fund after x years.
An example of a direct variation scenario is the increase in the income of a start-up bakeshop when the number of cakes sold increase. Example data are (4, $ 100), (5, $ 125), (6, $ 150), and (7, $ 175).
The example of indirect variation scenario is the decrease in time it takes to reach a destination when the speed of the mobile increases. This is shown in the data points: (10 kph, 10 mins), (12 kph, 8 mins), (14 kph, 6 mins), and (16 kph, 4 mins).
Top left:
7x-44 = 4x+4
7x-4x = 4+44
3x = 48
x = 16
8y-43 = 39+(7(16)-44)
8y = 39+68+43
8y = 150
y = 18.75
The formula is a permutation in which n represents the sample points in the set, while r represents the number of sample points in each permutation.
