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#1 Re: Help Me ! » Simplifying » 2015-02-06 07:47:14

Awesome! Thanks everyone!

#2 Re: Help Me ! » Simplifying » 2015-02-06 03:20:50

(sqrt 3).3(sqrt 3) - 15 (sqrt 3) + 7 (sqrt 3) - 35

3 x 3 - 15 (sqrt 3) + 7 (sqrt 3) - 35

9 - 8(sqrt 3) - 35

-8(sqrt 3) - 26

So the answer will be D?

#3 Re: Help Me ! » Simplifying » 2015-02-01 04:49:06

{3[SQRT(3)] + 7}  [SQRT(3) - 5]

First Part:
(sqrt 3).3(sqrt 3) + 15 (sqrt 3) + 7 (sqrt 3) + 35

Second Part:
3 x 3 + 15 (sqrt 3) + 7 (sqrt 3) + 35

Third Part:
9 + 22(sqrt 3) + 35

Fourth Part:
22(sqrt 3) + 44


Is this right?

#4 Re: Help Me ! » Simplifying » 2015-01-31 04:43:22

For #1 I still don't understand how to do it. Do you think you could show an example with a similar problem?


For #5 I am getting the answer 'F.'

#5 Re: Help Me ! » Simplifying » 2015-01-26 05:34:41

For #3 I came up to {4x[SQRT(7)]}/14y  which is answer A. Is that the correct answer?

#6 Help Me ! » Simplifying » 2015-01-22 02:38:57

demha
Replies: 11

Three of these I am not sure how to do, one of them I did my self and posted here just to make sure I got the right answer.




1. {3[SQRT(3)] + 7}[SQRT(3) - 5]

A -35
B -32
C 3[SQRT(3)] + 2
D -8[SQRT(3)] - 26
E 3[SQRT(3)] - 12
F 3[SQRT(9)] - 8[SQRT(3)] - 35





2. 4/[SQRT(5)]

A 4/[SQRT(5)]
B{4[SQRT(5)]}/25
C 4/25
D [SQRT(5)]/25
E {4[SQRT(5)]}/5
F 100/[SQRT(5)]


Answer: E


3. 4x/{2y[SQRT(7)]}

A{4x[SQRT(7)]}/14y
B 28x/14y
C 14x/y
D 4x/14y 
E [SQRT(14)}/14y
F 4x/y[SQRT(7)]



4. A weight hangs on a spring. The vibration period of that weight is the time in which it makes a complete cycle in motion. Suppose the relationship between the vibration period "T" (in seconds) and the weight "w" (in kilograms) is given by T = 2 pi SQRT(w / 200). Find the period T for a spring with a hanging weight of 2.0 kilograms.

A 0.3 seoconds
B 0.6 seconds
C 0.9 seconds
D 1.2 seconds
E 1.5 seconds
F 1.9 seconds





5. Suppose that the volume "V" (in cubic feet) of a blimp with radius "r" is given by V = 4/3 * pi * r^3. If the blimp has a volume of 10,000 cubic feet, find the approximate radius of the blimp.

A 13.98 feet
B 14.5 feet
C 62864.79 feet
D 5863.2 feet
E 29 feet
F 13.367


I am guessing of setting up the equation as:

10,000 = 4/3 x pi x r^3

#7 Re: Help Me ! » Radicals and Roots » 2014-10-07 02:57:02

#14
4x^2 - 16y^2
Square it to become:
2x - 4y
Which is answer 'A'?

#15
SQRT(8y) - SQRT(36)
2 x 4           9 x 4
2[SQRT(4y)] - 9[SQRT(4)]
Am I doig it right?

#8 Re: Help Me ! » Radicals and Roots » 2014-10-07 02:55:55

12.
I watched a video tutorial and got an idea of how to set it, tell me if I'm doing it right:

Then set it as:

Is this the correct way?

#9 Re: Help Me ! » Radicals and Roots » 2014-09-24 10:56:51

#9
Oh I get it! Instead of saying 1[SQRT(2)] it is just SQRT(2). So since the equation equals up to 0, there is nothing left, so the real answer is 'D'.

#10
This is how I thought of doing it:
2[SQRT(5)] + 3[SQRT(20)]
In the two sqrts, I looked for a same number that went into both of them, which was 5. So then I set it up like this:

2[SQRT(5)] + 3[SQRT(20)]
1 x 5              4 x 5
I take the 1 and 4 and square them to get 1 and 2, then add it together like:
1+2[SQRT(5)] + 2+3[SQRT(5)]
For the final answer of 8[SQRT950]
Is this a correct way of doing it and could it be applied to all similar problems?

---
Here are some more:

11. SQRT(12) - SQRT(27)
A SQRT(3)
B SQRT(12)
C SQRT(27)
D-SQRT(19)
E -SQRT(3)
F -SQRT(12)

My Answer: 'E'


12. SQRT(90a^4 b^7)
A 10a^2 b^3 [SQRT(9b)]
B 9a^4 b^6 [SQRT(9b)]
C 9a^2 b^3 [SQRT(9b)]
D 3a^2 b^3 [SQRT(10b)]
E 9a^4 b^6 [SQRT(10b)]
F 3a^4 b^6 [SQRT(10b)]

I'm not sure how to solve this one. It probably looks confusing. How can I set it up like you do to show a number that is to the power instead of adding this ^?

13. [SQRT(13) + SQRT(8)][SQRT(13) - SQRT(8)]
A 233
B 13 + SQRT(8) - SQRT(13)
C 21
D 169 + SQRT (64)
E 5
F 28

My Answer: 'E'


14. [SQRT(2x) + SQRT(4y)][SQRT(2x) - SQRT(4y)]
A 2x - 4y
B 2x + [SQRT(16xy)] + 4
C 2x - 8xy + 4y
D 2x - 2xy + 4y
E 2x - 2[SQRT(3xy)] + 4
F 2xy + 4xy

I want to show you how I got and how I solve it:
(2x + 4y)(2x - 4y)
2x * (2x + 4y) 4y * (2x - 4y)
(4x^2 + 8xy)(8xy - 16y^)
Cancel out the 8xy and left with:
4x^2 - 16y^2
Normally I would square this then add/subtract them to get a final answer. Since I have the ^2, what do I do instead? I don't see what my final answer would be in the list.


15. SQRT(2)[SQRT(4y) - SQRT(18)]
A 2y - 3
B SQRT(8y) - 6[SQRT(2)]
C SQRT(8y) - 6
D 2[SQRT(2y) - 6]
E SQRT(2y) - 3[SQRT(2)]
F 2[SQRT(2y)] - 6

Not sure how to solve this one. I thought of doing it this way:
SQRT(2)[SQRT(4y) - SQRT(18)]
work on [SQRT(4y) - SQRT(18)]  first:
SQRT(4y) - SQRT(18)
2 x 2 = 4      9 x 2 = 18 so
2[SQRT(2y)] - 9[SQRT(2)]
so now I am left with:
SQRT(2){2[SQRT(2y)] - 9[SQRT(2)]}
This is where I don't know how to proceed. Normally I would square the 9 and 2 then add/subtract them. But I'm just confused at this point.

#10 Re: Help Me ! » Radicals and Roots » 2014-09-24 03:50:07

So for #4 the answer would be 'D' 25a^2

And as for #5, I would then assume the answer is 'A' -27. But how is it in an earlier one (-125^2/3) the answer did not have a minus, the minus was turned into a positive?


Here are more:
6. 4[SQRT(3)] - 7[SQRT(3)]
A -9
B-11[SQRT(3)]
C-3[SQRT(3)]
D 9
E 11[SQRT(3)]
F 2[SQRT(3)]

Answer: 'C'



7. SQRT(5) * SQRT(5) * SQRT(9)
A 27
B 15
C SQRT(15)
D 25
E 5[SQRT(9)]
F SQRT(225)

Answer: 'B'



8. SQRT(196) + SQRT (441)
A 35
B 6[SQRT(49)]
C 7[SQRT(13)]
D 25
E 25[SQRT(12)]
F 5[SQRT(12)]

Answer: 'A'



9. SQRT(2) - 3[SQRT(2)] + 2[SQRT(2)]
A -4[SQRT(2)]
B SQRT(2)
C -SQRT(2)
D 0
E 4[SQRT(2)]
F -2[SQRT(2)]

Aswer: 'B'



10. 2[SQRT(5)] + 3[SQRT(20)]
A 8[SQRT(20)]
B 11[SQRT(20)]
C 5[SQRT(5)]
D 8[SQRT(5)]
E 14[SQRT(5)]
F 5[SQRT(20)]

I wasn't sure on how to do this one. I thought of a possible answer of 'D'. Weather this is correct or not, I would like to know how to solve this.

#11 Re: Help Me ! » Radicals and Roots » 2014-09-23 09:08:12

So that will be answer x^(3/2)

So you pretty much take the fraction and reduce it, am I correct? (From 6/4 to 3/2)

Here are some more:


4. (-3125a^5)^(2/5)
A 15a^3
B 5a
C 10a^2
D 25a^2
E 75a^3
F 125a^3

This one I was't really sure how to do since the larger number in parenthesis has the 5th power.


5. -2187(3/7)
A -27
B 312
C 21
D 27
E -21
F -312

My answer for this s 'D' 27.

#12 Re: Help Me ! » Radicals and Roots » 2014-09-23 05:22:48

So from what I understand, this how I THINK it goes:
-125^2/3
it becomes:
15,625 and I'm left with 1/3. So I need to find a number timed by itself 3 times to get 15,625 which is the answer, therefore being 'B' 25?

SO for that, I am given answers:
A 5
B 25
C -5
D -25
E 253
F 75



For the next problem, I am given:
x^(6/4)
with possible answers of:
A 6/4x
B x(2/3)
C 6x/4
D x(2)
E x(4/6)
F x(3/2)

How would I solve this with no number for 'x'?

EDIT:
For the first part, I believe it would be -25 not 25, so the answer would be 'D' -25.

#13 Re: Help Me ! » Radicals and Roots » 2014-09-23 02:39:52

So for that, my lesson gives me these answers to choose from:
A 3.83
B 4.5
C 18
D 10.90
E 4.8
F 1080

After square rooting twice, I got 3.8336 and a long list of numbers. So I just took the first three digits and matched it with 'A' as my answer.


Now another one goes like this:
(-125)^2/3
So, I believe it would be (-125)^2 which makes it 15,625 making it a positive. So it will be set up like:
x^3 = 15,625
How should I square root this?

#14 Re: Help Me ! » Radicals and Roots » 2014-09-22 14:04:19

Hi bobbym,

Where would I move on from there?
Should I do:
(6 * 6 * 6) = (216)^1/4? If so, where do I go from here?

#15 Help Me ! » Radicals and Roots » 2014-09-22 08:45:08

demha
Replies: 16

Need some more help. This is the first part. I would like an explanation of how to solve it:
Simplify
6^(3/4)

#16 Re: Help Me ! » Quick Question » 2014-09-19 02:09:53

3.9t - 15.6 = 0

SO we are solving for 't' here. Reordering:

-15.6 + 3.9t = 0

Add 15.6 to both sides:

15.6 + (-15.6) + 3.9t = 0 + 15.6

3.9t = 15.6

Divide each side by 3.9 for a final answer of:

t = 4

Answer: 'D'

#17 Re: Help Me ! » Quick Question » 2014-09-18 14:48:09

So with that I'll just solve for t and get my answer,correct?

#18 Help Me ! » Quick Question » 2014-09-15 10:45:56

demha
Replies: 5

I was given this word problem:

Suppose a football is kicked from the ground and its height in feet above the ground is given by h = -3.9t^2 + 15.6t. The height above the ground is "h". The time in seconds, after the ball is kicked, is "t". How long is the ball in the air?
A 10 seconds
B 5 seconds
C 18 seconds
D 4 seconds
E 15.6 seconds
F 3.9 seconds

I took
-3.9t^2 + 15.6t
and then factored -1t to be left with:
-1t(3.9t + 15.6)

From here I'm not all too sure where to go.

#19 Re: Help Me ! » Factoring Polynomials of Higher Degree » 2014-07-27 05:20:01

It's still not making too much sense for me. I tried putting in to this:
(a + b)(a2 – ab + b2)

But it just comes up into a huge mess:
(x^3)^3 + 1^3

((x^3)^3 + 1^3)(((x^3)^3)2 – ((x^3)^3)(1^3) + (1^3)^2)

#20 Re: Help Me ! » Factoring Polynomials of Higher Degree » 2014-07-26 07:24:02

Thanks ShivamS, but I want to understand how to find the answer. Like what steps am I supposed to take.

#21 Re: Help Me ! » Factoring Polynomials of Higher Degree » 2014-07-26 03:36:03

I come up with (x^3)^3 + 1^3 but I'm not entirely sure where to go from here.

#22 Help Me ! » Factoring Polynomials of Higher Degree » 2014-07-23 07:18:30

demha
Replies: 9

Hey guys, I need help with Factoring Polynomials of Higher Degree. I got around 20 questions and I'll post 5 at a time. For the first five I answered all but one:

1. 125x^3 + 64
A (5x - 4)(25x^2 + 20x - 16)
B(5x + 16)(25x^2 - 20x + 2)
C(5x + 8)(25x^2 - 40x + 16)
D(5x + 4)(25x^2 - 20x + 16)
E (5x + 2)(25x^2 - 40x + 16)
F cannot be factored

My answer is D.


2. 216a^3 + 1
A (3a + 1)(24a^2 - 8a + 1)
B(6a + 1)(36a^2 - 6a + 1)
C(18a + 1)(2a^2 - 6a + 1)
D(4a + 1)(20a^2 - 4a + 1)
E (6a - 1)(36a^2 + 6a + 1)
F cannot be factored

My answer is B.


3. 7x^5 - 64y
A 7xy(x^2 - 8)(x^2 + 8)
B 7x(x^2 - 8)(x^2 + 7)
C 7xy(x^4 - 8)
D 7x(x^2 - 9)(x^2 + 1)
E 7(x5 - 9x)
F cannot be factored

My answer is F.


4. 27x^3 - 8
A (3x - 2)(3x + 2)2
B(3x - 2)(9x^2 - 6x + 4)
C(3x + 2)(3x^2 - 3x - 4)
D(27x + 2)(x^2 - 2x + 4)
E (3x - 2)(9x^2 + 6x + 4)
F cannot be factored

My answer is E.


5. x^9 + 1
A (x + 1)(x^2 - x + 1)(x^6 - x^3 + 1)
B(x^3 + 1)(x^6 + 1)
C(x + 1)(x^2 - x + 1)(x^3-1)2
D(x + 1)3(x^2 - x + 1)3
E (x^3 + 1)(x^6 - x^3 + 1)
F cannot be factored

I am having a little trouble on this one. I'm not really sure how I would even begin with it.

#23 Re: Help Me ! » Factoring Quadratic Equations » 2014-07-04 06:42:37

Yeah the fraction was really confusing for me. Thank you very much for helping me out on this Maburo!

#24 Re: Help Me ! » Factoring Quadratic Equations » 2014-07-04 04:17:12

Awesome! Thank you very much for the help! It's definitely much easier for me now.

For 16, I got the answer 'C' [(2r + 3)(3r + 2) ].

For 18:
18. 5n^2 + 19n - 4   
A (n + 4)(5n - 1)
B (5n - 4)(n + 1)
C (5n - 4)(n - 1)
D (n - 4)(5n + 1)   
E (n - 2)(5n + 2)
F cannot be factored

I choose 'F' because there is nothing I can think of that will add up to 4 when times together and add up to 19 when added together.

19:
19. m^2 + (5/12)m - (1/6)    
A (m - 6)(m + 1)
B (m - 2/3)(m - 1/4)
C cannot be factored
D (m - 1/4)(m + 2/3)
E (m/12 + 2)(m/12 - 3)
F (m - 1/4)(m - 1/3)

I was having trouble trying to find the factors for these, I'm not too great with fractions.


20:
20. a^2 + 4a + 21
A (a + 7)(a - 3)
B a(a + 4) + 21
C (a + 21)(a - 1)
D (a + 3)(a - 7)
E (a + 7)(a + 3)
F cannot be factored   


Answer is 'F.'

#25 Help Me ! » Factoring Quadratic Equations » 2014-07-03 07:36:27

demha
Replies: 5

Hello everyone I'm back after a pretty long time big_smile

I haven't done math in quite a while so I'm going to need help with this. Basically I just need help to understand how to go through the equations step-by-step and then tell me if I'm right or wrong. Here they are:
12. 2x^2 + 23x - 12
A (2x - 6)(x + 2)
B(2x - 3)(x + 4) 
C(2x + 12)(x - 1) 
D(2x - 1)(x + 12)
E (x - 6)(x + 2)
F (2x - 1)(x - 12)

Answer:
2x^2 + 23x - 12
-1 and 24 are the common factors so:
2x^2 - x + 24x - 12
(2x^2 - x) + (24x - 12)
Factor Out:
x(2x - 1)+12(2x - 1)
The '(2x - 1)' is a common factor so we factor it out, being left with:
(2x - 1)(x + 12)
Final Answer Being D

Now from here on out I'm going to be needing some help.



13. a^2 + 4ab - 3b^2
A (a - 3b)(a - b)
B(a - b)(a + 3b)
C cannot be factored
D(a + b)(a + 3b)
E a(a + 4b) -3(-b)
F (a + b)(a - 3b)

I'm not sure how to get the answer using the equation problem. I do know how to work the factor answers backwards and came with the idea that the answer might be 'F.' I want to be sure if I am right and even if I am, I still want to understand how I can find the factors for this. I find it quite confusing mostly because of the double variables it has.


When we are done with the first two we can move on to the rest.

14. 9k^2 + 30kn + 25n^2
A (9k + 5n)(k + n)
B(3k - 5n)(3k + 5n)
C(3k - 5)(3k - 5)
D(3k + 5n)2 
E (9k + 25)(k + 1)
F (9k - 5)(9k - 5)


15. 2a^2-32
A 2(a^2 - 18)
B 2(a - 4)2
C (2a - 16)(a + 2)
D 2(a^2 - 16)
E 2(a - 4)(a + 4)
F cannot be factored


16. 6r^2 + 13r + 6
A 6(r^2 + 1) + 13
B(6r + 6)(r + 1)
C(2r + 3)(3r + 2)
D(2r + 2)(3r + 3)
E (6r + 1)(r + 6)
F cannot be factored


17. 4m^4 - p^2
A (4m2 - p)(m + p)
Bcannot be factored
C(2m^2 + p2)^2   
D(2m^2 - p2)^2
E (4m + p)(m3 - p)
F (2m^2-p)(2m^2+p)


18. 5n^2 + 19n - 4   
A (n + 4)(5n - 1)
B(5n - 4)(n + 1)
C(5n - 4)(n - 1)
D(n - 4)(5n + 1)   
E (n - 2)(5n + 2)
F cannot be factored


19. m^2 + (5/12)m - (1/6)    
A (m - 6)(m + 1)
B(m - 2/3)(m - 1/4)
Ccannot be factored
D(m - 1/4)(m + 2/3)
E (m/12 + 2)(m/12 - 3)
F (m - 1/4)(m - 1/3)


20. a^2 + 4a + 21
A (a + 7)(a - 3)
Ba(a + 4) + 21
C(a + 21)(a - 1)
D(a + 3)(a - 7)
E (a + 7)(a + 3)
F cannot be factored

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