Question

Victoria recently switched to a new electric company. If she uses between 0 and 400 kilowatt-hours (kWh) of electricity per month, the cost is a set price of $30. If she uses 400 kWh or more per month, the price is $0.097 per kWh.

Answer 1

see the explanation

Explanation:

The question is

Identify the domain and the range, using words and inequalities

Let

x -----> the number of kilowatt-hours (kWh) of electricity per month

y ----> the price per month

we know that

Part 1) For the value of x between 0 kWh and 400 kWh

`0\ kWh \leq x < 400\ kWh`

The price is equal to

`y=\$30`

therefore

The domain is the interval ------> [0,400)

The domain is all real numbers greater than or equal to 0 kWh and less than 400 kWh

The range is ($30)

The range is equal to $30

Part 2) For the value of x equal to 400 kWh or more per month

`x\geq 400\ kWh`

The domain is the interval -----> [400, infinite)

The domain is all real numbers greater than or equal to 400 kWh

The price is

`y=0.097x`

Find the range

For x=400 kWh

`y=0.097(400)=\$38.8`

so

`y\geq \$38.8`

The range is the interval -----> [38.8, infinite)