Answer :
Using a linear function, we have that:
- The inequality is: 54 ≤ C(x) ≤ 82.
- To stay within the range, the usage should be between 17.7 and 37.6 HCF.
What is a linear function?
A linear function is modeled by:
y = mx + b
In which:
- m is the slope, which is the rate of change, that is, by how much y changes when x changes by 1.
- b is the y-intercept, which is the value of y when x = 0, and can also be interpreted as the initial value of the function.
For the cost function, we have that:
- The fee of $29 is the intercept.
- The cost of $1.41 per HCF is the slope.
Hence the function is:
C(x) = 29 + 1.41x.
The recommended monthly bill for a household is between $54 and $82 dollars per month, hence the inequality is given by:
54 ≤ C(x) ≤ 82.
The bounds of the range will be found as follows:
29 + 1.41x = 54
x = (54 - 29)/1.41
x = 17.7.
29 + 1.41x = 82
x = (82 - 29)/1.41
x = 37.6.
Hence the correct option is:
To stay within the range, the usage should be between 17.7 and 37.6 HCF.
More can be learned about linear functions at https://brainly.com/question/24808124
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