Question

Will Give Medal To anyone who answers!

Answer 1

The volume of a rectangular box is (x3 - 7x2 - 9x + 63) cubic units. Determine the dimensions of the rectangular box by factoring the volume expression completely. Show your work.

Answer 2

So far this all I have
x^3-7x^2-9x+63
x^2(x-7)-9(x-7)
(x^2-9)(x-7)

Answer 3

@hedyeh99

Answer 4

@zepdrix

Answer 5

Not bad, you're nearly done now use difference of squares for (x^2-9)

Answer 6

how would I do that

Answer 7

Difference of square is (a+b)(a-b) = a^2-b^2 so you have (x^2-9) which is the same thing as (x^2-3^2) right? So what can we conclude :)

Answer 8

Umm, Im not sure, sorry Im not that great at this

Answer 9

\[(a^2-b^2) = (a+b)(a-b) \] this is what we get when we foil the left side out right?

Answer 10

Yes

Answer 11

So, now we back track

\[(x^2-9) \implies (x^2-3^2) \implies (x-3)(x+3)\]

x is your a, 3 is your b :)

Answer 12

ahh okay, i see

Answer 13

Right on, so your final answer now is (x-3)(x+3)(x-7)

Answer 14

That would be the answer to the question? Or would it need to be simplified further? @iambatman

Answer 15

Well now you would need the roots, which you just said each factor = 0, and solve for x.

You'll get, 3,-3, and 7.

Answer 16

So, those would be my answers to the whole question?

Answer 17

Yeah since they want the dimensions those are it.

Answer 18

Okay, Thank you very much :)

Answer 19

Np ^.^

Answer 20

Btw if you're interested in reading about difference of squares here is a link: http://www.regentsprep.org/regents/math/algebra/AV6/Lfactps.htm