Question

Joan uses the function C(x) = 0.11x + 12 to calculate her monthly cost for electricity.• C(x) is the total cost (in dollars).• x is the amount of electricity used (in kilowatt-hours).Which of these statements are true? Select the three that apply.A. Joan's fixed monthly cost for electricity use is $0.11.B. The cost of electricity use increases $0.11 each month.C. If Joan uses no electricity, her total cost for the month is $12.D. Joan pays $12 for every kilowatt-hour of electricity that she uses.E. The initial value represents the maximum cost per month for electricity.F. A graph of the total cost for x ≥ 0 kilowatt-hours of energy used is a straight line.G. The slope of the function C(x) represents the increase in cost for each kilowatt hour used.

Answer 1

The correct statements are:

C. If Joan uses no electricity, her total cost for the month is $12.

F. A graph of the total cost for x ≥ 0 kilowatt-hours of energy used is a straight line.

G. The slope of the function C(x) represents the increase in cost for each kilowatt hour used.

Explanation:

Notice that the given function is the equation of a line in the slope-intercept form:

`C(x)=0.11x+12`

From this interpretation, we'll have that the correct statements are:

C. If Joan uses no electricity, her total cost for the month is $12.

F. A graph of the total cost for x ≥ 0 kilowatt-hours of energy used is a straight line.

G. The slope of the function C(x) represents the increase in cost for each kilowatt hour used.