Find the volume of a rectangular prism if the length is [tex]4x[/tex], the width is [tex]5x[/tex], and the height is [tex]x^2 + x + 2[/tex]. Use the formula [tex]V = l \cdot w \cdot h[/tex], where [tex]l[/tex] is length, [tex]w[/tex] is width, and [tex]h[/tex] is height, to find the volume.

A. [tex]20x^3 + 20x^2 + 40x[/tex]
B. [tex]20x^4 + 20x^2 + 40x^2[/tex]
C. [tex]20x^4 + x + 29[/tex]
D. [tex]20x^2 + 9x^2 + 18x^2[/tex]



Answer :

To find the volume of a rectangular prism, we use the formula:

[tex]\[ V = \text{length} \times \text{width} \times \text{height} \][/tex]

Given:
- Length ([tex]\( l \)[/tex]) = [tex]\( 4x \)[/tex]
- Width ([tex]\( w \)[/tex]) = [tex]\( 5x \)[/tex]
- Height ([tex]\( h \)[/tex]) = [tex]\( x^2 + x + 2 \)[/tex]

We substitute these values into the volume formula:

[tex]\[ V = (4x) \times (5x) \times (x^2 + x + 2) \][/tex]

First, multiply the length and width:

[tex]\[ 4x \times 5x = 20x^2 \][/tex]

Next, multiply this result by the height:

[tex]\[ V = 20x^2 \times (x^2 + x + 2) \][/tex]

Now, distribute [tex]\( 20x^2 \)[/tex] through each term in the polynomial [tex]\(x^2 + x + 2\)[/tex]:

[tex]\[ V = 20x^2 \cdot x^2 + 20x^2 \cdot x + 20x^2 \cdot 2 \][/tex]

This simplifies to:

[tex]\[ V = 20x^2 \cdot x^2 + 20x^2 \cdot x + 20x^2 \cdot 2 \][/tex]
[tex]\[ V = 20x^4 + 20x^3 + 40x^2 \][/tex]

Thus, the volume of the rectangular prism is:

[tex]\[ \boxed{20x^4 + 20x^3 + 40x^2} \][/tex]

However, notice that the choices given have different forms. Based on the available choices, the one that matches our final calculation is:

[tex]\[ 20x^2(x^2 + x + 2) \][/tex]

Rewriting our final result:
[tex]\[ 20x^4 + 20x^3 + 40x^2 \][/tex]
matches:

[tex]\[ 20x^2(x^2 + x + 2) \][/tex]

Given the choices, the correct answer expressed differently:
[tex]\[ 20x^2(x^2 + x + 2) \][/tex]

Thus the answer is:
[tex]\[ \boxed{20 x^2(x^2 + x + 2)}\][/tex]