Question #ec7ee

1 Answer
Mar 8, 2017

The dimensions are 12x " by " 8x " by " 4x inches.

Explanation:

Let's look at the actual dimensions of the carton first.

The length of the carton will be the width of three dictionaries placed side by side. 4+4+4 = 12 inches

The width of the carton will be the length of one book: 8 inches

The height will be the thickness of four books on top of each other:
1+1+1+1 = 4 inches

So the carton is 12 " by " 8 " by " 4 inches.

As a polynomial we have to write the dimensions of each book in terms of x.
Let's call the thickness x
The width of each book is therefore 4x
and the length is 8x

The dimensions of the box are therefore:

Length: 4x+4x+4x = 12x
Width: 8x
Height: x+x+x+x=4x

We can only write a single polynomial if we know what we are doing with the separate dimensions.

If it is the volume of the carton, it would be:

V = lxxbxxh = 12x xx 8x xx 4x = 384x^3

If it is the total surface area it would be:

TSA = 2(lb+lh +bh) = 2(12x xx 8x + 12x xx 4x +8x xx 4x)

=2(96x^2 +48x^2 +32x^2)

=2(176x^2) = 352x^2