The storage space in a moving truck is shaped like a rectangular prism. It has a total volume of 16 cubic meters. The height and width are both 2 meters less than the depth. What are the dimensions of the storage space?​

Respuesta :

Answer:

The dimensions are four by two by two meters.

Step-by-step explanation:

The volume for a rectangular prism is given by:

[tex]V=\ell wh[/tex]

Where l is the length (or depth), w is the width, and h is the height.

Since the height and width are both two meters less than the depth, we can write that:

[tex]h=\ell -2\text{ and } w = \ell -2[/tex]

We are also given that the total volume is 16 cubic meters. Substitute:

[tex]16=\ell(\ell -2)(\ell -2)[/tex]

Expand:

[tex]16=\ell(\ell^2 -4\ell +4)[/tex]

Distribute:

[tex]16=\ell ^3-4\ell ^2+4\ell[/tex]

Isolate the equation. So:

[tex]\ell ^3-4\ell ^2+4\ell -16=0[/tex]

We can factor by grouping. From the first two terms, factor out a l² and from the last two terms, factor out a 4:

[tex]\ell ^2(\ell -4)+4(\ell -4)=0[/tex]

Factor:

[tex](\ell ^2+4)(\ell -4)=0[/tex]

Zero Product Property:

[tex]\ell ^2+4=0\text{ or } \ell - 4=0[/tex]

Solve for each case:

[tex]\ell^2=-4\text{ or } \ell =4[/tex]

Since we cannot take the square root of a negative number, we can ignore the first case.

Therefore, the length (or depth) of the storage space is four meters.

Thus, the dimensions are four by two by two meters.