Question #ec7ee

1 Answer
Mar 8, 2017

The dimensions are 12x " by " 8x " by " 4x12x 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 = 124+4+4=12 inches

The width of the carton will be the length of one book: 88 inches

The height will be the thickness of four books on top of each other:
1+1+1+1 = 41+1+1+1=4 inches

So the carton is 12 " by " 8 " by " 412 by 8 by 4 inches.

As a polynomial we have to write the dimensions of each book in terms of xx.
Let's call the thickness xx
The width of each book is therefore 4x4x
and the length is 8x8x

The dimensions of the box are therefore:

Length: 4x+4x+4x = 12x4x+4x+4x=12x
Width: 8x8x
Height: x+x+x+x=4xx+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^3V=l×b×h=12x×8x×4x=384x3

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

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

=2(176x^2) = 352x^2=2(176x2)=352x2