In order to do this problem you need to understand slope intercept form.
Slope intercept form is y = mx +b.
y is the y-value
m is the slope of the function
x is the x-value
b is the y-intercept.
- when simply writing the function we do not need to provide the x and y variables. What we need to provide are the constants. That is the slope and y-intercept. Considering that no initial cost to join the gym was provided in the problem, we can assume there is no upfront cost. Therefore, at x = 0, y = 0. This means that our b-value is 0 so we can ignore it when writing our equation. Since we know x represents the number of months that has elapsed since the start of the gym membership we need to know the cost per month. The cost per month is 20. Therefore the slope is 20.
f(x) = 20x
2.A fee increase of 25% would affect the monthly cost. Therefore we can simply add 25% of the value of the membership payment to the monthly cost. 20*0.25 = 5. 20 +5 = 25
The new function: g(x) = 25x
