Multiplying and Dividing Polynomials

zee-f · 2011-07-16 22:39:22

1. 3x(8x^2 2x)
A24x^3 6x^2
B24x^2 6x
C24x^3 + 6x^2
D24x^1 6x^2 + 3
E24x^2 + 6x^2
F24x 6x

2. -6x2(4x2 9)
A24x^4 - 54x^2
B-24x^4 + 54x^2
C24x^2 - 54x^2
D24x^3 + 54x^2
E-24x^4 - 54x^2
F-24x^2 + 54x

3.(3x + 6x)/3x
A6
B1
C3x
D6x
Ex
F3

4. (21x^3 + 14x) / 7
A 3 + 2x^2
B 3x^2 + 2x
C 3x + 2x
D 3x^3 + 2x
E 3 + 2x
F 3

5. (4x^5 + 8x^2) / 4x
Ax^4 + 2x
Bx^2 + 2x
C4x^4 + 2x
Dx^4 - 2x
E-4x^4 - 2x
Fx^2 + 2

6. (x + 1)(x 3)
Ax^2 + 3
Bx^3 2x + 3
Cx^2 2x 3
Dx^4 + 2x 3
Ex^2 2x + 3
Fx^2 3

7. (x 4)(x 4)
Ax^2 + 16
Bx^2 8x + 16
Cx^2 - 16
Dx^2 + 8x + 16
Ex^2 16x
Fx^2 + 8x

8. (3x 6)(8x + 2)
A 24x^2 - 42x 12
B 24x^2 - 42x + 12
C 24x^2 + 42x 12
D -24x^2 + 42x 12
E 24x^2 + 42x + 12
F- 24x^2 + 42x + 12

9. (2x + 5)(-x + 4)
A-2x^2 - 3x - 20
B2x^2 + 3x + 20
C2x^2 + 3x - 20
D-2x^2 + 3x + 20
E-2x^2 + 3x + 9
F2x^2 + 3x + 1

10. (-x 5)(-x + 5)
Ax^2 + 25
Bx^2 - 10x 25
Cx^2 + 10x 25
Dx^2 25
E-x^2 + 10x 25
F-x^2 25x

11. [2(x 1) + 3(x 1)] / (x 1)
A6
B1
Cx - 1
D-1
E5
F-6

12. [3(2x 3) x(2x 3)] / (2x - 3)
A3x
Bx - 3
C2x - 3
D3 - x
Ex
F3

13. [x^2(5x + 6) 3(5x + 6)] / (5x + 6)
Ax^2 + 3
B3x^2
C-x^2 + 3
D-x^2 3
Ex^2 3
F3x^2 3

14. [3x^2(2x - 3) + 27x^3(2x - 3)] / [3x(3 2x)]
A -x - 9x^2
B9x^2
Cx 9x^2
D -x - 3x^2
E9x^2
Fx + 9x^2

15.

A

B

C

D

E

F

*(its the first image )

In problems 16-20, describe the mistakes, if any.

16. (-x + 4)(x + 2) = x^2 + 2x + 8
AThere should be a "+6" instead of a "+8."
BThere should be a "+6x" instead of a "+2x."
CThere should be a "-8" instead of a "+8"
DThere should be a negative with the x^2
EThere should be a "-6" instead of a "+8"
FThis solution is correct.

17. (3x^2 + 7)(9 8x) = 3x^2 56x + 63
AThere should be a "3x^3" term in the answer.
BThere should be a "-63" term in the answer instead of "+63".
CThere should be a "+56x" term in the answer instead of "-56x".
DThere should be a "-16" term in the answer.
EThere should be a "-24x^3" term in the answer.
FThis solution is correct.

18. (second image )

ABoth of the x's in the 9x^2 term cannot be cancelled, so the answer should be 9x 8.
BSince we have (6-x), we must multiply through by a negative, so the answer should be 17.
COnly one of the x's in the 9x^2 term can be cancelled, so the answer should be x.
DOnly one of the x's in the numerator can be cancelled, so the answer should be 1x.
EThe expression cannot be simplified.
FThis solution is correct.

19.(third image)

ATo cancel (7-x) with (x- 7), a negative must be taken out of the bottom, so the answer should be -5.

BTo cancel (7-x) with (x- 7), a negative must be taken out of the bottom, so the answer should be -19.

CTo cancel (7-x) with (x- 7), a negative must be taken out of the bottom, so the answer should be +5.

D(x-7) will not cancel with (7 x), so the answer should be (forth image )

EThe expression cannot be simplified.
FThis solution is correct.

zee-f · 2011-07-16 22:42:25

the pictures

zee-f · 2011-07-16 22:48:21

#15-

a- 2x+5/x-1

b- x^2-5x-14/x-1

c- x^2+5x-14/x-1

d- x^2+5x+14/x-1

e-x^2+5x+14/x+1

f- 2x-5/x-1

bobbym · 2011-07-16 23:04:36

Hi;

1) A
2) B
3) F
4) D
5) A
6) C
7) B
8) A
9) D
10) D
11) E
12) D
13) E
14) A
15) F ( I do not like how that answer is formatted. )

How many did you get right out of the first 15? Which did you get wrong?

zee-f · 2011-07-17 02:00:46

i didnt submit it yet i have to finish all 20 to submit it

bobbym · 2011-07-17 09:18:28

Hi;

16) D
17) E, this is the best answer.
18) A
19) B

zee-f · 2011-07-17 10:27:21

hey thank you for the help for number 20 i chose f is that correct ???

(x+1)(x-1)-(x+1)(x+2) / (x+1)(x-7)= -3\x-7

AAfter the polynomials are multiplied, they must be simplified, so the answer should be 1/x-7

BAfter the polynomials are multiplied, they must be simplified, so the answer should be -1/x-7

CThe polynomials should be multiplied, so the answer should be (x^2-1) - (x^2+3x+2)/ x^2-6x-7

D(x - 1) and (x + 2) cannot be combined after canceling the (x + 1) terms, so the answer should be
(x-1)-(x+2)/x-7

EThe expression cannot be simplified.
FThis solution is correct.

bobbym · 2011-07-17 10:40:44

Hi;

There are some errors in how you are formatting the problem. Do not replace / with \.

Is this the question?

If that is what you meant then you are correct!

zee-f · 2011-07-18 02:53:01

thank you ALLLLLOOOOT i got a 20

reconsideryouranswer · 2011-07-18 02:58:46

zee-f, the name of this thread is "Help Me!"
not "Do it for me."

You should always show your own attempts and where
you're stuck.

No posters here should be giving you the answers.

bobbym · 2011-07-18 08:31:24

Hi reconsideryouranswer;

No posters here should be giving you the answers.

Normally that would be true. But in this case look who is helping. Bob Bundy and myself.

The rules of posting conduct:

http://www.mathisfunforum.com/viewtopic.php?id=14654

MIF, Bob Bundy and I wrote those rules! He is a teacher so he ought to know a goofer from someone who is actually trying. I post on many forums and also have a feel for who is in earnest and who is slacking off. Sometimes I will answer questions even when I think it is homework. Even when I think the OP is just going to copy the answer down and go back to facebook. Why? Because other members and guests read those posts too. They may be really needing the help.

Also you can never tell how a person will end up, I was a major slacker. Probably the best in the world. No one helped me and maybe they should have.

I do use some techniques to get the OP at least interested in math. Sometimes all that is needed is some human interaction.

Math Is Fun Forum

#1 2011-07-16 22:39:22

Multiplying and Dividing Polynomials

#2 2011-07-16 22:42:25

Re: Multiplying and Dividing Polynomials

#3 2011-07-16 22:48:21

Re: Multiplying and Dividing Polynomials

#4 2011-07-16 23:04:36

Re: Multiplying and Dividing Polynomials

#5 2011-07-17 02:00:46

Re: Multiplying and Dividing Polynomials

#6 2011-07-17 09:18:28

Re: Multiplying and Dividing Polynomials

#7 2011-07-17 10:27:21

Re: Multiplying and Dividing Polynomials

#8 2011-07-17 10:40:44

Re: Multiplying and Dividing Polynomials

#9 2011-07-18 02:53:01

Re: Multiplying and Dividing Polynomials

#10 2011-07-18 02:58:46

Re: Multiplying and Dividing Polynomials

#11 2011-07-18 08:31:24

Re: Multiplying and Dividing Polynomials

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