Question

The volume of a rectangular prism is b^3 + 8b^2 + 19b + 12 cubic units, and its height is b + 3 units.
The area of the base of the rectangular prism is ?square units.

Answer 1

Can some one help me set this up?
b^3 + 8b^2 + 19b + 12 = (b+1)(b+3)(b+4)

Answer 2

@iGreen are u busy?

Answer 3

HELP PLEASE ON MY QUESTION I GREEN AND I DONT KNNOW HOW TO TAG

Answer 4

Just type in '@iGreen' on your question.

Answer 5

Okay, well we already have the length(b + 1) the width(b + 4) and the height(b + 3).

Now we can plug this into the Surface Area formula.

\(SA = 2(wh + lw + lh)\)

\(SA = 2[(b + 4)(b + 3) + (b + 1)(b + 4) + (b + 1)(b + 3)]\)

Multiply all 3 pairs of binomials together.

\(SA = 2[(b^2 + 7b + 12) + (b^2 + 5b + 4) + (b^2 + 4b + 3)]\)

Add like terms:

\(SA = 2[(b^2 + b^2 + b^2) + (7b + 5b + 4b) + (12 + 4 + 3)]\)

\(SA = 2[3b^2 + 16b + 19]\)

Now multiply 2 to each term, can you do that?

Answer 6

im back sorry looking at it now thanks

Answer 7

That's fine, I just posted it.

Answer 8

so now I need to multiply 2 to each term? 2(3b^2+16b+19)

Answer 9

6b^2+32b+38

Answer 10

Yep.

\(2(3b^2 + 16b + 19)\rightarrow (2 \times 3b^2) + (2 \times 16b) + (2 \times 19)\)

Answer 11

Yep, so your answer is \(SA = 6b^2 + 32b + 38\).

Answer 12

I wish but that wasn't one of my answers. Ive been going crazy since yesterday.

Answer 13

What..what are your answer choices?

Answer 14

b^2+5b+4
(b^2+5b+4+24)/(b+3)
(b^2-5b+4-24)/(b+3)
(-b^2+11b-52+168)/(b+3)

Answer 15

Ohhhhhh.....

Answer 16

see insane!!!!!

Answer 17

Hold on, let me test something out.

Answer 18

ok thanks

Answer 19

Okay, I have no idea..lol. Sorry..

Answer 20

Its OK thanks for trying I really appreciate it!!!

Answer 21

@Supreme_Kurt @ganeshie8 @campbell_st @iambatman @perl

Answer 22

Actually, @KitKat16
You've already done the hard part of this blasted question XD
You've already factored the thing, and you know which factor is the height... so....

We know that the length and width of the rectangular base are (b+1) and (b+4)

...right?

Answer 23

yes

Answer 24

@Supreme_Kurt all my questions are insane ask @iGreen lol

Answer 25

So, you're asked for the AREA of the rectangular base, and you know the length and width...

Can't get any smoother than that ;)

Answer 26

One tag's enough KitKat, just call me Kurt ^

Answer 27

(b+1)b+3)(b+4)

Answer 28

ok

Answer 29

You got the length, width, and height.

Answer 30

Why'd you include b+3?
That gives you the volume lol

The length and width of the rectangular base are just b+1 and b+4 .


So...

Answer 31

b^2+5b+4

Answer 32

Exactly ;)
Nice job.

Answer 33

omg it was that easy. Thanks guys you are awesome! Thanks for always being there Green

Answer 34

Hehe, no problem :)