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=l×b×h=12x×8x×4x=384x3

If it is the total surface area it would be:

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

=2(96x2+48x2+32x2)

=2(176x2)=352x2