Question

Wendy is logging the number of video game levels she wins per hour. She has determined the function to be f(x) = 6x + 9, where x represents hours and f(x) represents the number of video game levels won. Which of the following options describes the restrictions to the domain and range correctly?

A) Domain, nonnegative values; range, values greater than −1.5
B) Domain, nonnegative values; range, values less than −1.5
C) Domain, nonnegative values; range, values greater than or equal to 9
D)Domain, nonnegative values; range, values less than or equal to 9

Answer 1

The answer is C because spending no time on video games gets you at least 9 for a range, and spending as much time as she wants to means the number will increase meaning "greater than"

Answer 2

Let

x--------> represents hours

f(x)------> represents the number of video game levels won

we know that

`f(x)=6x+9`

this is the equation of a line

The slope m is equal to
`m=6\ (level\ won)/(hours)`

the domain is the interval-----------> [0, ∞)

the range is the interval--------> [9, ∞)

using a graph tool see the attached figure

therefore

the answer is the option

C) Domain, nonnegative values; range, values greater than or equal to 9