A rectangular prism has dimensions [tex]\( x \)[/tex] units, [tex]\( 2x \)[/tex] units, and [tex]\( x + 8 \)[/tex] units.

Which expression represents the surface area of the prism?

A. [tex]\( 8x + 16 \)[/tex] square units
B. [tex]\( 16x + 32 \)[/tex] square units
C. [tex]\( 10x^2 + 48x \)[/tex] square units
D. [tex]\( 2x^3 + 16x^2 \)[/tex] square units



Answer :

To determine the surface area of a rectangular prism with dimensions [tex]\( x \)[/tex] units, [tex]\( 2x \)[/tex] units, and [tex]\( x+8 \)[/tex] units, we will follow the formula for calculating the surface area of a rectangular prism. The surface area [tex]\( A \)[/tex] is given by:

[tex]\[ A = 2(lw + lh + wh) \][/tex]

Where:
- [tex]\( l \)[/tex] is the length
- [tex]\( w \)[/tex] is the width
- [tex]\( h \)[/tex] is the height

For this problem:
- [tex]\( l = x \)[/tex]
- [tex]\( w = 2x \)[/tex]
- [tex]\( h = x + 8 \)[/tex]

Now, substitute [tex]\( l \)[/tex], [tex]\( w \)[/tex], and [tex]\( h \)[/tex] into the surface area formula:

[tex]\[ A = 2 \left( (x)(2x) + (x)(x + 8) + (2x)(x + 8) \right) \][/tex]

Calculate each term inside the parentheses:

[tex]\[ (x)(2x) = 2x^2 \][/tex]

[tex]\[ (x)(x + 8) = x^2 + 8x \][/tex]

[tex]\[ (2x)(x + 8) = 2x^2 + 16x \][/tex]

Now add these results together:

[tex]\[ 2x^2 + x^2 + 8x + 2x^2 + 16x \][/tex]

Combine like terms:

[tex]\[ (2x^2 + x^2 + 2x^2) + (8x + 16x) = 5x^2 + 24x \][/tex]

So the expression inside the parentheses is now [tex]\( 5x^2 + 24x \)[/tex]. Now multiply by 2 to get the final surface area:

[tex]\[ A = 2(5x^2 + 24x) \][/tex]

Distribute the 2:

[tex]\[ A = 10x^2 + 48x \][/tex]

Thus, the expression that represents the surface area of the prism is:

[tex]\[ 10x^2 + 48x \, \text{square units} \][/tex]

Hence, the correct answer is:

[tex]\[ 10 x^2 + 48 x \, \text{square units} \][/tex]

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