Select the correct answer.

The area of a tiled kitchen floor is represented by the expression [tex]4x^2 + 24x + 27[/tex], where [tex]x[/tex] represents the length of a single tile. The length, [tex]l[/tex], of the floor is 9 feet more than twice the length of a tile, [tex]x[/tex].

Which expression represents the width of the kitchen in terms of [tex]x[/tex]?

A. [tex]2x + 3[/tex]
B. [tex]2x - 3[/tex]
C. [tex]2x + 9[/tex]
D. [tex]2x - 9[/tex]



Answer :

To find the correct expression representing the width of the kitchen floor in terms of [tex]\( x \)[/tex], we need to follow these steps:

1. Understand the given area expression:
The given area of the kitchen floor is [tex]\( 4x^2 + 24x + 27 \)[/tex].

2. Determine the length of the kitchen floor:
It is given that the length [tex]\( l \)[/tex] of the floor is 9 feet more than twice the length of a tile [tex]\( x \)[/tex].
Therefore, the length [tex]\( l \)[/tex] can be expressed as:
[tex]\[ l = 2x + 9 \][/tex]

3. Find the width by dividing the area by the length:
The area of a rectangle is given by the formula:
[tex]\[ \text{Area} = \text{Length} \times \text{Width} \][/tex]
Let [tex]\( w \)[/tex] represent the width. Then,
[tex]\[ 4x^2 + 24x + 27 = (2x + 9) \times w \][/tex]
To find [tex]\( w \)[/tex], we divide the area expression by the length:
[tex]\[ w = \frac{4x^2 + 24x + 27}{2x + 9} \][/tex]

4. Factor the quadratic expression:
We need to factor [tex]\( 4x^2 + 24x + 27 \)[/tex]. Let's try to factor it:
[tex]\[ 4x^2 + 24x + 27 = (2x + 3)(2x + 9) \][/tex]
We can check this factorization by expanding it back:
[tex]\[ (2x + 3)(2x + 9) = 2x \cdot 2x + 2x \cdot 9 + 3 \cdot 2x + 3 \cdot 9 = 4x^2 + 18x + 6x + 27 = 4x^2 + 24x + 27 \][/tex]
The factorization is correct.

5. Determine the width:
Recall, we had:
[tex]\[ 4x^2 + 24x + 27 = (2x + 9) \times w \][/tex]
Substituting the factorized form:
[tex]\[ (2x + 3)(2x + 9) = (2x + 9) \times w \][/tex]
We can see that:
[tex]\[ w = 2x + 3 \][/tex]

Therefore, the expression representing the width [tex]\( w \)[/tex] of the kitchen in terms of [tex]\( x \)[/tex] is:
[tex]\[ 2x + 3 \][/tex]

Thus, the correct answer is [tex]\( 2x + 3 \)[/tex].