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#