A rectangular bird feeder costs [tex]\$18.00[/tex]. A cylindrical bird feeder costs [tex]\$24.00[/tex]. The expected cost to keep the rectangular bird feeder filled is [tex]\$3.00[/tex] per week. The expected cost to keep the cylindrical bird feeder filled is [tex]\$2.00[/tex] per week. The equation below models the break-even point.

[tex]
18 + 3x = 24 + 2x
[/tex]

What does [tex]x[/tex] represent?

A. The total cost to fill the rectangular bird feeder after any number of weeks.
B. The total cost to fill the cylindrical bird feeder after any number of weeks.
C. The number of weeks the bird feeders are filled.
D. The number of bird feeders purchased each week.



Answer :

Certainly! Let's work through the problem by analyzing the given equation and determining what [tex]\( x \)[/tex] represents.

The given equation is:
[tex]\[ 18 + 3x = 24 + 2x \][/tex]

Here:
- [tex]\( 18 \)[/tex] represents the initial cost of the rectangular bird feeder.
- [tex]\( 3x \)[/tex] represents the ongoing cost to maintain the rectangular bird feeder over [tex]\( x \)[/tex] weeks, where [tex]\( x \)[/tex] is the number of weeks.
- [tex]\( 24 \)[/tex] represents the initial cost of the cylindrical bird feeder.
- [tex]\( 2x \)[/tex] represents the ongoing cost to maintain the cylindrical bird feeder over [tex]\( x \)[/tex] weeks, where [tex]\( x \)[/tex] is the number of weeks.

We are asked to determine the value of [tex]\( x \)[/tex] to find the break-even point between the two bird feeders' total costs over time.

Let's solve the equation step by step:

1. Start with the equation:
[tex]\[ 18 + 3x = 24 + 2x \][/tex]

2. Subtract [tex]\( 2x \)[/tex] from both sides to get all [tex]\( x \)[/tex]-terms on one side:
[tex]\[ 18 + 3x - 2x = 24 + 2x - 2x \][/tex]
[tex]\[ 18 + x = 24 \][/tex]

3. Subtract 18 from both sides to isolate [tex]\( x \)[/tex]:
[tex]\[ 18 + x - 18 = 24 - 18 \][/tex]
[tex]\[ x = 6 \][/tex]

The solution [tex]\( x = 6 \)[/tex] represents the number of weeks at which both bird feeders will have the same total cost. Therefore, [tex]\( x \)[/tex] is:

[tex]\[ \text{The number of weeks the bird feeders are filled.} \][/tex]

Hence, the correct interpretation of [tex]\( x \)[/tex] is:
[tex]\[ \boxed{\text{the number of weeks the bird feeders are filled}} \][/tex]