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edjones answered: 7568 problems
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Polynomials-and-rational-expressions/456556: We are working on rational expression and equations this week and I am completely lost with the following problem.
1. Divide and simplify
b+3/b-9 / 9b+27/b-4
2. Solve the equation and check your answer.
q+6/7 + q-2/2=8/7
3. Add. 6/z+3 + 9/7z
4. Subtract. Simplify, if possible.
g/s+g - g/s-g
These are the last ones I need help with, thank you very much for the help.
1 solutions

Answer 313335 by edjones(7569) About Me  on 2011-06-02 01:06:10 (Show Source):
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4)
g/s+g - g/s-g
g(s-g)-g(s+g)/(s+g)(s-g)
(gs-g^2-gs-g^2)/(s^2-g^2)
=-2g^2/(s^2-g^2)
or 2g^2/(g^2-s^2)
.
Ed


Radicals/456581: 2 √25 + 3 √25
1 solutions

Answer 313332 by edjones(7569) About Me  on 2011-06-02 00:54:38 (Show Source):
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2 √25 + 3 √25
=5sqrt(25)
=25
.
Ed


Radicals/456587: what is 32 squared divided by 2 squared?
1 solutions

Answer 313331 by edjones(7569) About Me  on 2011-06-02 00:53:02 (Show Source):
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32^2/2^2
=1024/4
=256
.
Ed


Polynomials-and-rational-expressions/456589: i need to factor this out the problem is 6a^2+7a-3 and im just getting stuck
1 solutions

Answer 313330 by edjones(7569) About Me  on 2011-06-02 00:51:11 (Show Source):
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6a^2+7a-3
6*-3=-18. Two factors of -18 whose sum is 7 are +9 and -2.
6a^2+9a-2a-3
=3a(2a+3)-(2a+3)
=(3a-1)(2a+3)
.
Ed


Permutations/456585: There are 15 teams in the Eastern Conference of the National Hockey League for 2006-2007 season, divided into 3 divisions of 5 teams each. Eight of these teams will participate in the playoff. The division winner from each division goes to the playoff; in addition the next 5 ranked teams in the conference, based on regular season records will participate in the playoffs. How many different collections of eight teams from the Eastern Conference could go to the playoffs?
1 solutions

Answer 313328 by edjones(7569) About Me  on 2011-06-02 00:45:22 (Show Source):
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5^3=125 possible combinations of division winners.
12C5=792 Next 5 ranked teams in the conference.
.
792+125=917 possible combinations (with the Boston Bruins winning it all this year)
.
Ed


Probability-and-statistics/456565: why cant you calculate median for nominal level data?
1 solutions

Answer 313327 by edjones(7569) About Me  on 2011-06-02 00:35:21 (Show Source):
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Since nominal data such as a list of names has no numerical value then an average name or the median name have no meaning. The list does have a mode however, the commonest name in the list.
.
Ed


Permutations/456579: An advertising firm based in Boston has 12 advertising agents. Next week, agents must meet with 3 prospective clients in Orlando, Chicago, and Seattle. The firm will send 3 agents to Orlando, 4 to Chicago, and 3 to Seattle. Assuming no agent will travel to more than one destination, how many different arrangements of agents are possible to meet with 3 prospective clients?
1 solutions

Answer 313318 by edjones(7569) About Me  on 2011-06-01 23:57:35 (Show Source):
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10C3 * 7C4 * 3C3
=120*35
=4200
.
Ed


Geometry_Word_Problems/456561: The volume of a box is 192 cubic inches. the hight is 4 inches the width is 2 inches more than the length. Find the missing dimensions.
1 solutions

Answer 313317 by edjones(7569) About Me  on 2011-06-01 23:54:03 (Show Source):
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4*2=8
192/8=24 the missing dimension.
.
Ed


Quadratic_Equations/456575: I have been working on a problem and I cannot figure out how to get an approximated answer to three decimals. Can you show me how to get this.
This is what I have so far.
In the right trianle, find the length of the side not given. Give an exact answer and an approximation to 3 decimal places.
a = 13 b = 13 a+b=c 13^2+13^2=c^2 169+169=c^2
169+169=338 338=c^2
This is what I have so far. Take the square root of both sides c=338. The exact value of c is the sqrt of 338. The value approximated to three decimals is ?
Am I doing this problem correctly? If I am I do not know how to get the value appoximated to three decimals. Can you help me please?
1 solutions

Answer 313315 by edjones(7569) About Me  on 2011-06-01 23:42:37 (Show Source):
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sqrt(338)=18.385
Get a scientific calculator.


Radicals/456574: 11√7 - 3√7
1 solutions

Answer 313314 by edjones(7569) About Me  on 2011-06-01 23:36:16 (Show Source):
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11√7 - 3√7
=8sqrt(7)


Radicals/456568: sqrt( 15 )- sqrt ( 3/5 )
1 solutions

Answer 313313 by edjones(7569) About Me  on 2011-06-01 23:34:36 (Show Source):
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sqrt( 15 )- sqrt ( 3/5 )
=sqrt(15)-sqrt(3)/sqrt(5)
=(sqrt(75)-sqrt(3))/sqrt(5)
=(5sqrt(3)-sqrt(3))/sqrt(5)
=4sqrt(3)/sqrt(5)
=4sqrt(3)/sqrt(5) * sqrt(5)/sqrt(5)
=4sqrt(15)/5
.
Ed


Permutations/456559: In how many ways can the letters in the word “DIFFERENCE” be arranged?

1 solutions

Answer 313312 by edjones(7569) About Me  on 2011-06-01 23:26:47 (Show Source):
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There are 10 letters. There are 3 Es, 2 Fs
10!/(3!*2!)=302400
.
Ed


Functions/456480: Find the domain and range of:
f(x)=sqrt(x-2)
1 solutions

Answer 313292 by edjones(7569) About Me  on 2011-06-01 21:23:44 (Show Source):
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The domain is x[2, infinity) square root of a negative number is not allowed.
The range is y[0, infinity)
.
Ed
.
graph%28500%2C500%2C-10%2C10%2C-10%2C10%2Csqrt%28x-2%29%29


Number-Line/456450: 1. What integer is one-third of the distance from 4 to 2 on the number line?
2. What integer is three-fourths of the distance from 5 to 19 on the number line?
1 solutions

Answer 313253 by edjones(7569) About Me  on 2011-06-01 18:49:34 (Show Source):
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1)4-2=2
2 * 1/3 = 2/3
2 2/3 not an integer.
.
19-5=14
14 * 3/4 = 21/2 = 10 1/2
5 + 10 1/2 = 15 1/2 not an integer.
.
Ed


Radicals/456448: what's -3radical of 120 ?
1 solutions

Answer 313248 by edjones(7569) About Me  on 2011-06-01 18:43:54 (Show Source):
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-3sqrt(120)
=-3sqrt(4*30)
=-6sqrt(30)
.
Ed


Radicals/456436: (3 radical 5+ 2 radical 3)(3 radical 5 -2 radical 3)
1 solutions

Answer 313245 by edjones(7569) About Me  on 2011-06-01 18:41:24 (Show Source):
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Let sqrt(5)=f and sqrt(3)=t
(3f+2t)(3f-2t)
=9f^2-4t^2
=9*5-4*3
=45-12
=33
.
Ed


Probability-and-statistics/456318: QUESTIONS 1-5 ARE BASED ON THE FOLLOWING INFORMATION
The fill in bottles of a wine is normally distributed with mean μ = 750 milliliters (ml) and standard deviation of σ = 9 ml.

1 For samples of size n = 64 bottles selected from this population, the mean of the sampling distribution of x̄ is _____ and the standard error of x̄ ______.

a E(x̄) = 93.75 se(x̄) = 9
b E(x̄) = 750 se(x̄) = 9
c E(x̄) = 750 se(x̄) = 0.141
d E(x̄) = 750 se(x̄) = 1.125

2 "The probability that the mean of a sample of n = 64 bottles falls between 748 and 752 ml is,
P(748 < x̄ < 752) = _____."

a 0.9500
b 0.9250
c 0.8165
d 0.7154

3 The proportion of the means obtained from samples of size n = 64 bottles that fall within ±1 ml from the mean of the population of bottles is _____.

a 0.6827
b 0.6266
c 0.5223
d 0.4039

4 The margin of error for the interval which contains 80% of all sample means is: MOE = _______.
a 2.21 ml.
b 1.85 ml.
c 1.44 ml.
d 1.29 ml.

5 To obtain a margin of error MOE = ± 1 ml for an interval that contains 95% of all sample means, the sample size is n = _____.

a 312
b 217
c 159
d 122


1 solutions

Answer 313234 by edjones(7569) About Me  on 2011-06-01 18:26:49 (Show Source):
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1)s=9/sqrt(64)=9/8=1.125
m=750
.
2)
z=2/1.125=1.78
area under curve for +-1.78=.9250
.
3)
1/1.125 = .89
area under curve for +-0.89=0.6266
.
4)
For the area under the curve of 0.8 the z=+-1.28
1.28 * 9/8 = 1.44 ml
.
5)
For the area under the curve of 0.95 the z=+-1.96
1.96 * 9/sqrt(x)=1 ml
sqrt(x)=1.96*9=17.64
x=311.17=312 always round up.
.
Ed


Pythagorean-theorem/456328: Please help me solve this equation: +x%5E2-2x-3=+sqrt%28+4+%29+.
1 solutions

Answer 313216 by edjones(7569) About Me  on 2011-06-01 17:09:16 (Show Source):
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x^2-2x-3= sqrt( 4 )
x^2-2x-3=2
x^2-2x =5
x^2-2x+1=5+1 completing the square.
(x-1)^2=6
x-1=+-sqrt(6)
x=1+sqrt(6), x=1-sqrt(6)
.
Ed


Exponential-and-logarithmic-functions/456330: log(7)x=2
1 solutions

Answer 313214 by edjones(7569) About Me  on 2011-06-01 17:03:23 (Show Source):
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log[7](x)=2
7^log[7](x)=7^2
x=7^2
=49
.
Ed


Triangles/456343: the ratio of the measures of the sides of a triangle is 2:5:6. If the length of the longest side is 48 inches, find the perimeter

1 solutions

Answer 313213 by edjones(7569) About Me  on 2011-06-01 17:00:09 (Show Source):
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48/6=8
8*2=16
8*5=40
p=48+40+16
=104"
.
Ed


Proportions/456365: 2:x = 10:35
1 solutions

Answer 313204 by edjones(7569) About Me  on 2011-06-01 16:17:23 (Show Source):
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2/x=10/35
2/x=2/7
x/2=7/2
x=7
.
Ed


test/456353: k^2-k+2k^2-2k
1 solutions

Answer 313203 by edjones(7569) About Me  on 2011-06-01 16:15:07 (Show Source):
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k^2-k+2k^2-2k
=3k^2-3k


Probability-and-statistics/456360: At a picnic a cooler filled with ice there are 100 cans of soda. With a mixture of sodas. 30 cans of cola, 40 cans of orange, 20 cans of root beer and 10 cans of cream soda. What are the odds of, if you reach in and you select just ONE can, and that can is either a cola or a orange soda?
This is what I have done so far.
N= 100, r= 30
= 30/100 = 3/10 =0.3
n=100, r=40
= 40/100= 4/10 = 0.4
= 0.3 + 0.4 = 0.7 times chance of getting either a cola or a can of orange soda.
-------------------------------------------------------------------------------
Please help me!
1 solutions

Answer 313200 by edjones(7569) About Me  on 2011-06-01 16:10:25 (Show Source):
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P=70/100=7/10 probability of success.
3/10 probability of failure.
Odds in favor of success are 7/10 to 3/10 or simply 7 to 3.
.
Ed



Equations/456094: I am having trouble with solving for x in the following equation:
+%28x%2B1%29%2F%28x-3%29=x%2B2+
So far I have tried the following steps to simplify:
x+1=(x+2)(x-3)
x+1=x%5E2-3x%2B2x-6
x+1=x%5E2-x-6
x+7=x%5E2-x
2x+7=x%5E2
2+7=x%5E2%2Fx
9=x%5E2%2Fx
9x=x%5E2
9=x
However, when I plug this solution for x into a calculator I end up with %289%2B1%29%2F%289-3%29=+5%2F3, which is not = to 9+2.
I hope you can explain this to me! I've been trying for hours over the past couple of days and I'm just not understanding it.
Thank you for taking the time to read this.
1 solutions

Answer 313090 by edjones(7569) About Me  on 2011-05-31 22:56:41 (Show Source):
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(x+1)/(x-3)=x+2
x+1=(x-3)(x+2)
x+1=x^2-x-6
x^2-2x-7=0
x=1-2sqrt(2), x=1+2sqrt(2) see below
.
Ed
.
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B-2x%2B-7+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%28-2%29%5E2-4%2A1%2A-7=32.

Discriminant d=32 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28--2%2B-sqrt%28+32+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%28-2%29%2Bsqrt%28+32+%29%29%2F2%5C1+=+3.82842712474619
x%5B2%5D+=+%28-%28-2%29-sqrt%28+32+%29%29%2F2%5C1+=+-1.82842712474619

Quadratic expression 1x%5E2%2B-2x%2B-7 can be factored:
1x%5E2%2B-2x%2B-7+=+1%28x-3.82842712474619%29%2A%28x--1.82842712474619%29
Again, the answer is: 3.82842712474619, -1.82842712474619. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-2%2Ax%2B-7+%29


test/456047: X2= 25
1 solutions

Answer 313087 by edjones(7569) About Me  on 2011-05-31 22:45:01 (Show Source):
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x^2=25
x=5, x=-5
.
Ed


Human-and-algebraic-language/456075: A bag contains 2 red marbles,4 green marbles, and 4 blue marbles. You choose one marble at random, put the marble back into the bag, then choose a second marble at random. what is the probability that you choose 2 red marbles?
1 solutions

Answer 313086 by edjones(7569) About Me  on 2011-05-31 22:42:51 (Show Source):
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There are 10 marbles. Two are red.
2/10=1/5
(1/5)^2
=1/25 the probability that you choose 2 red marbles.
.
Ed


Permutations/456064: A true-false test contains 12 questions. In how many
different ways can this be completed?
1 solutions

Answer 313084 by edjones(7569) About Me  on 2011-05-31 22:39:58 (Show Source):
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2^12=4096 ways


Average/456087: 24 is 2.5% of what number?
1 solutions

Answer 313082 by edjones(7569) About Me  on 2011-05-31 22:37:55 (Show Source):
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.025x=24
x=960
.
Ed


Probability-and-statistics/456085: If Fred makes every 4 out of 5 free throws in basketball that he attempts. What is the probability that Fred will make the next 2 free throws he attempts?
1 solutions

Answer 313079 by edjones(7569) About Me  on 2011-05-31 22:35:38 (Show Source):
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(4/5)^2=16/25


Linear-systems/456037: how do you find the slope of 4x+20y=5?
1 solutions

Answer 313045 by edjones(7569) About Me  on 2011-05-31 20:22:52 (Show Source):
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y=mx+b Slope-intercept form. The slope is m.
4x+20y=5
20y=5-4x
y=5/20 - 4x/20
y=1/4 - x/5 The slope is -1/5.
.
Ed


Polynomials-and-rational-expressions/456022: How do you solve rational expression using Lowest Common Denominator and cross multiplying?
5/a^2= (-4/a) +1
5 over a squared = (negative 4 over a) plus 1
1 solutions

Answer 313040 by edjones(7569) About Me  on 2011-05-31 20:18:11 (Show Source):
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5/a^2= (-4/a) +1
5=-4a+a^2 Multiply each side by a^2.
a^2-4a-5=0
(a-5)(a+1)=0
a=5, a=-1
.
Ed