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#1 2012-12-06 22:56:10
- demha
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Multiplying and Dividing Polynomials
I am having a hard time understanding how to do these correctly. Could someone please help explain how to do them step by step?
1. (3x + 6x)/3x
2. (21x3 + 14x) / 7
3. (4x5 + 8x2) / 4x
4. [2(x – 1) + 3(x – 1)] / (x – 1)
5. [3(2x – 3) – x(2x – 3)] / (2x - 3)
6. [x2(5x + 6) – 3(5x + 6)] / (5x + 6)
7. [3x2(2x - 3) + 27x3(2x - 3)] / [3x(3 – 2x)]
If you dream about beating me, you better wake up and apologize.
-Muhammad Ali
#2 2012-12-07 00:29:40
- bob bundy
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Re: Multiplying and Dividing Polynomials
hi demha
OK let's start with Q1
Now you could simplify the top first but, looking at the later ones, it is probably better to split into two fractions.
Can you finish this one from here?
Bob
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
#3 2012-12-09 17:51:18
- demha
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Re: Multiplying and Dividing Polynomials
Sorry I haven't answered sooner. I have been busy with other matters.
To finish from there. If I'm correct, we have to reduce it.
So:
3x/3x + 6x/3x
Reducing:
1x/1x + 3x/1x
For first fraction:
1x goes into 1x one time so it will become just x.
For second fraction:
1x goes into 3x three times so it will become 3x.
So the problem becomes x + 3x. So the answer is 4x?
If you dream about beating me, you better wake up and apologize.
-Muhammad Ali
#4 2012-12-09 17:58:33
- Agnishom
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Re: Multiplying and Dividing Polynomials
For first fraction:
1x goes into 1x one time so it will become just x.
No it will become 1
Similarly, 6x/3x = 2
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#5 2012-12-09 21:03:56
- demha
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Re: Multiplying and Dividing Polynomials
So you don't reduce them?
So then:
3x/3x + 6x/3x
For first fraction:
3x goes into 3x 1 time.
For second fraction:
3x goes into 6x 2 times.
Then it becomes 1 + 2 and of course the answer is 3.
If you dream about beating me, you better wake up and apologize.
-Muhammad Ali
#7 2012-12-10 20:06:42
- demha
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Re: Multiplying and Dividing Polynomials
So that would be set as:
21x^3/7 + 14x/7
For the first fraction:
7 goes into 21x 3x times I suppose. This will leave it with 3x^3?
For the second fraction:
7 goes into 14x 2x times.
The problem then becomes:
3x^3 + 2x
They are not entirely alike so you can't add them. Therefor that is the answer I believe?
If you dream about beating me, you better wake up and apologize.
-Muhammad Ali
#8 2012-12-10 20:16:33
- bob bundy
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Re: Multiplying and Dividing Polynomials
hi demha,
Yes, that's correct, well done.
The others are similar, although the expressions get more complicated.
How about trying Q3 and Q4 and then I'll check them.
Bob
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
#9 2012-12-10 22:57:09
- demha
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Re: Multiplying and Dividing Polynomials
3.
(4x^5 + 8x^2) / 4x
4x^5/4x + 8x^2/4x
For first equation:
4x goes into 4x 1 time so it will be 1^5
For second equation:
4x goes into 8x 2 times so it will be 2^2.
It will then be:
1^5 + 2^2
I hope I did this one correct.
Number 4 seems to be pretty complicated. I'm not too sure how to start it!
If you dream about beating me, you better wake up and apologize.
-Muhammad Ali
#10 2012-12-11 00:36:02
- bob bundy
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Re: Multiplying and Dividing Polynomials
hi demha,
You shouldn't have lost the xs. Have a look at this:
Cancel the 4 top and bottom and one x top and bottom to leave
Bob
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
#12 2012-12-11 13:14:19
- bobbym
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Re: Multiplying and Dividing Polynomials
That is correct!
In mathematics, you don't understand things. You just get used to them.
Probability is the most important concept in modern science, especially as nobody has the slightest notion what it means.
90% of mathematicians do not understand 90% of currently published mathematics.
#15 2012-12-12 21:17:39
- demha
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Re: Multiplying and Dividing Polynomials
2(x – 1) + 3(x – 1) / (x – 1)
2(x – 1)/(x - 1) + 3(x – 1)/( x - 1)
For the first fraction:
so (x - 1) goes into (x - 1) one time making it 2(1). Now I want to stop right here and make sure that I'm doing this right.
If you dream about beating me, you better wake up and apologize.
-Muhammad Ali
#17 2012-12-13 16:46:41
- demha
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Re: Multiplying and Dividing Polynomials
Glad to know I'm on the right track.
Second part of the equation:
3(x – 1)/( x - 1)
Same way, (x - 1) goes into (x - 1) 1 time making it 3(1).
So now the equation is:
2 + 3 and the final answer will be 5.
Am I correct?
If you dream about beating me, you better wake up and apologize.
-Muhammad Ali
#18 2012-12-13 18:20:12
- bobbym
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Re: Multiplying and Dividing Polynomials
Hi;
Correct! Very good!
In mathematics, you don't understand things. You just get used to them.
Probability is the most important concept in modern science, especially as nobody has the slightest notion what it means.
90% of mathematicians do not understand 90% of currently published mathematics.
#20 2012-12-13 19:59:09
- demha
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Re: Multiplying and Dividing Polynomials
#5
[3(2x – 3) – x(2x – 3)] / (2x - 3)
First fraction:
3(2x - 3)/(2x - 3)
(2x - 3) goes into (2x - 3) 1 time.
3(1)
Second fraction:
x(2x - 3)/(2x - 3)
(2x - 3) goes into (2x - 3) 1 time.
x(1)
Answer:
3 - x
#6
[x2(5x + 6) – 3(5x + 6)] / (5x + 6)
First fraction:
x^2(5x + 6)/(5x + 6)
(5x + 6) goes into (5x + 6) 1 time.
x^2(1)
Second fraction:
3(5x + 6)/(5x + 6)
(5x + 6) goes into (5x + 6) 1 time.
3(1)
x^2 - 3
#7
[3x^2(2x - 3) + 27x^3(2x - 3)] / [3x(3 – 2x)]
This one seems a little confusing.
---
I also have two more having some trouble with:
8. 15x^7 – 45x^5 / 3x4
19. (3x – 2)(x - 4) – (x - 4)(6 – 5x) / (4 – x)(8x – 1)
If you dream about beating me, you better wake up and apologize.
-Muhammad Ali
#21 2012-12-13 20:17:18
- bob bundy
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Re: Multiplying and Dividing Polynomials
#5
[3(2x – 3) – x(2x – 3)] / (2x - 3)
First fraction:
3(2x - 3)/(2x - 3)
(2x - 3) goes into (2x - 3) 1 time.
3(1)
Second fraction:
x(2x - 3)/(2x - 3)
(2x - 3) goes into (2x - 3) 1 time.
x(1)
Answer:
3 - x
correct!
#6
[x2(5x + 6) – 3(5x + 6)] / (5x + 6)
First fraction:
x^2(5x + 6)/(5x + 6)
(5x + 6) goes into (5x + 6) 1 time.
x^2(1)
Second fraction:
3(5x + 6)/(5x + 6)
(5x + 6) goes into (5x + 6) 1 time.
3(1)
x^2 - 3
correct!
#7
[3x^2(2x - 3) + 27x^3(2x - 3)] / [3x(3 – 2x)]
This one seems a little confusing.
At this stage you can divide each part and then simplify.
(3-2x) goes into (2x-3) exactly minus 1 times
Let's get this one finished and then we can look at 8 and 9.
Bob
---
I also have two more having some trouble with:
8. 15x^7 – 45x^5 / 3x4
19. (3x – 2)(x - 4) – (x - 4)(6 – 5x) / (4 – x)(8x – 1)
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
#22 2012-12-13 21:38:21
- demha
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Re: Multiplying and Dividing Polynomials
[3x^2(2x - 3) + 27x^3(2x - 3)] / [3x(3 – 2x)]
First one:
3x^2(2x - 3)/3x(3 – 2x)]
So since it is (2x - 3) and (3 - 2x), it goies into it but it becomes a -1? And as for the 3x^2 and 3x, would this becomes x^2?
If you dream about beating me, you better wake up and apologize.
-Muhammad Ali
#23 2012-12-13 22:05:42
- demha
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Re: Multiplying and Dividing Polynomials
Wait, I think it just becomes x(-1)
27x^3(2x - 3) / 3x(3 – 2x)
(2x - 3) goes into (3 - 2x) -1 time. 3x goes into 27 9 times and takes down the ^3 to ^2 which makes it 9^2(-1)
-x + -9^2
Is that correct?
If you dream about beating me, you better wake up and apologize.
-Muhammad Ali