Answer: -4.1
Step-by-step explanation:
0.4 - 4.5 = -4.1
Using linear function concepts, it is found that:
- a) It costs $0.1 for each kilowatt hour of electricity used in excess of 250 kWh.
- b) f(90) = 46.6, which is the cost of 340 kWh of consumption in a month.
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A <em>linear function </em>has the format given by:

In which:
- m is the slope, which is the rate of change, that is, how much y changes when x changes by 1.
- b is the y-intercept, which is the value of y when x = 0.
The equation for the cost of h kilowatt hours (kWh) of electricity used in excess of 250 kWh is of:

Item a:
- The slope is of
, which means that it costs $0.1 for each kilowatt hour of electricity used in excess of 250 kWh.
Item b:

250 + 90 = 340.
f(90) = 46.6, which is the cost of 340 kWh of consumption in a month.
A similar problem is given at brainly.com/question/24808124
Answer:
f(7) = 158
Step-by-step explanation:
To evaluate f(7) substitute t = 7 into f(t)
f(7) = 3(7)² + 11 = (3 × 49) + 11 = 147 + 11 = 158