Get detailed and reliable answers to your questions with IDNLearn.com. Join our community to access reliable and comprehensive responses to your questions from experienced professionals.

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]


Sagot :

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].