ptebwwong said:

I need help with this problem:

The volume of a rectangular box is 64ft^3. If the width is 3 times longer than the height, and the length is 9 times longer than the height, find the dimensions of the box.

I don't even know how to start.

Start by naming things. In this case name the height of the box whatever you desire. For instance...

Let h represent the height of the box.

Now, then, name the length in terms of h.

Then name the width in terms of the length.

After you have named these things, you can build your equation based on the fact that you know the volume of a box is length X width X height.