Question

How do you find the volume of a prism if the width is x, height is `2x-1` and the length if `3x+4`?

Answer 1

I'm assuming here that you mean a square prism:

For every prism, the volume is given by the formula:
`"Volume" = "Area" times "Length"`
where `"Area"` is the area of the cross-section: the figure you would have if you were to slice a little piece off the prism.

In this case, the cross section is a rectangle. The area of a rectangle can be calculated by doing `"height" times "width"`.

So, the formula for these kind of prisms becomes:
`Volume = w*h*l`
where `w = "width", h = "height"` and `l = "length"`.

Entering your values into the formula:
`x*(2x-1)*(3x+4)`

You can bring the `x` inside the first parentheses:
`(2x^2-x)*(3x+4)`
And now, you can use FOIL.
`6x^3 + 5x^2 - 4x`

This is the volume.
I hope this is what you meant, and that it helped.