Given : Fix amount charges = $200.
Each month additional charge = $50.
Let us assume number of months are taken by x.
So, we can setup a function as
Total charge = Fix charge + each month charge * number of months.
f(x) = 200 + 50*x
Or f(x) = 200 +5x.
Where function f is the total charge of x number of months.
The values of x's represents domain and function value represents range.
According to problem, it is said " first three months".
So, we need to take number of months as x=0,1,2,3.
And we need to find values of function for those x values.
On plugging x=0,1,2 and 3 we would get
f(0) = 200 +5(0) = 200 +0 = 200.
f(1) = 200 +5(1) = 200 +50 = 250.
f(2) = 200 +5(2) = 200 +100 = 300.
f(3) = 200 +5(3) = 200 +150 = 350.
We got function values 200,250,300 and 350.
Therefore, with respect to the given situation, the domain of the funtion is
{0,1,2,3} and Range { 200,250,300, 350}.
