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Answer 373086 by jim_thompson5910(28476) on 2012-03-10 12:00:20 (Show Source):
You can put this solution on YOUR website!I'm assuming you want to graph this equation.
Looking at  we can see that the equation is in slope-intercept form  where the slope is  and the y-intercept is
Since  this tells us that the y-intercept is ) .Remember the y-intercept is the point where the graph intersects with the y-axis
So we have one point
Now since the slope is comprised of the "rise" over the "run" this means
Also, because the slope is  , this means:
which shows us that the rise is 1 and the run is 3. This means that to go from point to point, we can go up 1 and over 3
So starting at ) , go up 1 unit
and to the right 3 units to get to the next point
Now draw a line through these points to graph
 So this is the graph of  through the points ) and
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If you need more help, email me at jim_thompson5910@hotmail.com
Also, please consider visiting my website: http://www.freewebs.com/jimthompson5910/home.html and making a donation. Thank you
Jim
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Quadratic_Equations/585018: c) Calculate the value of if the difference between the roots of x^2-6x+k=0
is 3.
1 solutions
Answer 373029 by jim_thompson5910(28476) on 2012-03-10 00:30:33 (Show Source):
You can put this solution on YOUR website!p-q = 3
(x-p)(x-q)
x^2-xp-xq+pq
x^2-(p+q)x+pq
-(p+q)=-6
p+q=6
p-q=3
2p=9
p = 9/2
p+q = 6
9/2+q = 6
q = 6-9/2
q = 3/2
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(x-p)(x-q)
x^2-xp-xq+pq
x^2-(p+q)x+pq
x^2-(9/2+3/2)x+(9/2)(3/2)
x^2-6x+27/4
So the value of 'k' is
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Linear-equations/584971: (-2,0),(0,4) 1 solutions
Answer 373026 by jim_thompson5910(28476) on 2012-03-10 00:07:34 (Show Source):
You can put this solution on YOUR website!
First let's find the slope of the line through the points ) and
Note: ) is the first point ) . So this means that  and  .
Also, ) is the second point ) . So this means that  and  .
 Start with the slope formula.
 Plug in  ,  ,  , and
 Subtract  from  to get
 Subtract  from  to get
 Reduce
So the slope of the line that goes through the points ) and ) is
Now let's use the point slope formula:
 Start with the point slope formula
 Plug in  ,  , and
 Rewrite  as
 Distribute
 Multiply
 Simplify
So the equation that goes through the points ) and ) is
Notice how the graph of  goes through the points ) and ) . So this visually verifies our answer.
 Graph of  through the points ) and
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Quadratic_Equations/585004: In questions 6-9, use the discriminant to determine the number of solutions of the quadratic equation, and whether the solutions are real or complex. Note: It is not necessary to find the roots; just determine the number and types of solutions.
The above is the instructions for the problems. Below I have worked out each math problem, but once again, I'm not sure whether or not the solutions I have are real or complex. I think I worked each problem out correctly. If I have not please let me know. If I have, I guess the only thing I need clarifying on is if the solution I have is real or complex.
6. x²+6x-7=0
Use the quadratic formula to find the solutions.
X=-b±√b²-4ac ax²+bx+c=0
2a
A=1, B=6, C=-7
b²-4ac The discriminant of a quadratic is the expression inside the radical of the quadratic formula.
((6)²-4(1)(-7)) Substitute in the values of a,b, and c.
36-4(1)(-7) Squared 6
36-4(-7) Multiplied 1 by -7
36+28 Multiplied -4 by each term inside the parenthesis.
64 Added 36+28
ANSWER: 64 Real or complex????
7.z²+z+1=0
Use the quadratic formula to find the solutions.
X=-b±√b²-4ac ax²+bx+c=0
2a
A=1, B=1, C=1
b²-4ac The discriminant formula
((1)²-4(1)(1)) Substitute in the values of a,b, and c
1-4(1)(1) Expand the exponent 2 to the expression
1-4(1) Multiply 1*1
1-4 Multiply -4 by each term inside the parenthesis
-3 Subtract 4 from 1
ANSWER: -3 Real or complex??
8. (3)½y²-4y-7(3)^½=0
√(3)*y²-4y-7(3)^½=0 An expression with a fractional exponent can be written as a radical with an index equal to the denominator of the exponent
√3*y²-4y-7(3)^½=0 Removed the parenthesis around the expression 3
√3*y²-4y+(-7*√(3))=0 Reduced
√3*y²-4y+(-7*√3)=0 Removed the parenthesis around the expression 3
√3*y²-4y+(7√3)=0 Multiplied -7 by √
y²√3-4y-7√3=0 Multiplied √3 by y²
Y=-b±√b²-4ac ay²+bx+c=0
2a
A=√3, B=-4, C=-7√3
b²-4ac Discriminant formula
((-4)²-4(√3)(-7√3)) Substitute in the values of a,b,c
(4)(-4)-4(√3)(-7√3) Squared
16-4(√3)(-7√3) Multiply to simplify the expression (-4)(-4)
16-4(-7√3²) Multiply -7W to get -7W²
16+28√3² Multiplied -4 by each term inside the parenthesis.
16+28(3) Squared
16+84 Multiplied 28 by each term inside the parenthesis.
ANSWER: 100 Real or complex???
9. 2x²-10x+25=0
X=-b±√b²-4ac ax²+bx+c=0
2a
A=2, B=-10, C=25
b²-4ac
((-10)²-4(2)(25)) Substitute in the values of a,b, and c.
(-10)(-10)-4(2)(25) Squared
100-4(2)(25) Multiplied to simplify the expression (-10)(-10)
100-4(50) Multiplied 2 by25
100-200 Multiplied -4 by each term inside the parenthesis.
ANSWER: -100 real or complex??
1 solutions
Answer 373025 by jim_thompson5910(28476) on 2012-03-09 23:23:48 (Show Source):
You can put this solution on YOUR website!The quantity  is the determinant. This determines whether your solutions are real or complex. If  is positive, then you'll have two real solutions. In the first problem (#6), you found that  . Since this is a positive number, this means that you have two real solutions.
On the other hand, for problem #9, you got -100. This means that there are 2 complex solutions.
Hope this clears things up a bit. If not, let me know.
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Probability-and-statistics/584957: In a study of internet users, researchers discovered that 80% of users own at least one computer ans that 25% of users log onto the internet for more that 30 hrs per week. Suppose that 15% of users own at least one computer AND log onto the internet for more that 30 hrs per wk. Given that an internet user owns at least one computer, what is the probability that he\she logs onto the internet for more than 30hrs per week?
I know that P(I and C) = P(I) X P(I|C) but I am having trouble figuring out the numbers.
Thank you 1 solutions
Answer 373001 by jim_thompson5910(28476) on 2012-03-09 19:06:49 (Show Source):
You can put this solution on YOUR website!P(I|C) = P(I and C)/P(C)
P(I|C) = 0.15/0.8
P(I|C) = 0.1875
So the probability that the user logs on for more than 30 hrs a week, given that the internet user owns at least one computer, is 0.1875 (which is an 18.75% chance)
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Money_Word_Problems/584952: My monthly disability went from $468.00 to $ 492.00. What is the percentage of the raise? I know it rose by $24, but I can't figure out the percentage.
Thank you!
1 solutions
Answer 372993 by jim_thompson5910(28476) on 2012-03-09 18:44:28 (Show Source):
You can put this solution on YOUR website!Percent Increase = [(New - Old)/(Old)]*100
Percent Increase = [(492-468)/468]*100
Percent Increase = [24/468]*100
Percent Increase = [0.05128]*100
Percent Increase = 5.128%
So it rose roughly 5.128%.
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Triangles/584932: One equilateral triangle has sides 5 ft long. Another equilateral triangle has sides 7 ft long. Find the ratio of the areas of the triangles. I think I need to start with the similarity ratio. But I'm not sure, and I don't know where to go from there! Thank you. (: 1 solutions
Answer 372986 by jim_thompson5910(28476) on 2012-03-09 17:10:31 (Show Source):
You can put this solution on YOUR website!If the side length of an equilateral triangle is x units, then the height/altitude is (x/2)*sqrt(3) units.
So the area is then A = (bh)/2 = (x*(x/2)*sqrt(3))/2 = ((x^2)/4)*sqrt(3)
So in short, the area of the equilateral triangle with side length 'x' is ((x^2)/4)*sqrt(3) square units.
So the triangle with sides 5 ft long has an area of ((5^2)/4)*sqrt(3) = (25/4)*sqrt(3)
and the triangle with sides 7 feet long has an area of ((7^2)/4)*sqrt(3) = (49/4)*sqrt(3)
Divide the two to get ( (25/4)*sqrt(3) )/( (49/4)*sqrt(3) ) = (25/4)(4/49) = 25/49
So the ratio between the two areas is 25:49
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Trigonometry-basics/584928: 4xsquared+36x+35 i need two numbers that multiply to 56 but add to 36 (x+?)(x+?) 1 solutions
Answer 372984 by jim_thompson5910(28476) on 2012-03-09 17:03:40 (Show Source):
You can put this solution on YOUR website!
Looking at the expression  , we can see that the first coefficient is  , the second coefficient is  , and the last term is  .
Now multiply the first coefficient  by the last term  to get  .
Now the question is: what two whole numbers multiply to  (the previous product) and add to the second coefficient  ?
To find these two numbers, we need to list all of the factors of  (the previous product).
Factors of  :
1,2,4,5,7,10,14,20,28,35,70,140
-1,-2,-4,-5,-7,-10,-14,-20,-28,-35,-70,-140
Note: list the negative of each factor. This will allow us to find all possible combinations.
These factors pair up and multiply to  .
1*140 = 140
2*70 = 140
4*35 = 140
5*28 = 140
7*20 = 140
10*14 = 140
(-1)*(-140) = 140
(-2)*(-70) = 140
(-4)*(-35) = 140
(-5)*(-28) = 140
(-7)*(-20) = 140
(-10)*(-14) = 140
Now let's add up each pair of factors to see if one pair adds to the middle coefficient  :
| First Number | Second Number | Sum | | 1 | 140 | 1+140=141 | | 2 | 70 | 2+70=72 | | 4 | 35 | 4+35=39 | | 5 | 28 | 5+28=33 | | 7 | 20 | 7+20=27 | | 10 | 14 | 10+14=24 | | -1 | -140 | -1+(-140)=-141 | | -2 | -70 | -2+(-70)=-72 | | -4 | -35 | -4+(-35)=-39 | | -5 | -28 | -5+(-28)=-33 | | -7 | -20 | -7+(-20)=-27 | | -10 | -14 | -10+(-14)=-24 |
From the table, we can see that there are no pairs of numbers which add to  . So  cannot be factored.
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Answer:
So doesn't factor at all (over the rational numbers).
So is prime.
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Probability-and-statistics/584924: If one vase contains 3 red, 4 pink and 5 white roses and another vase has 2 red, 2 pink and 2 white roses, what is probability that one rose chosen from each vase will be the same color? Please explain how to come to the answer. Thank you. 1 solutions
Answer 372977 by jim_thompson5910(28476) on 2012-03-09 16:16:17 (Show Source):
You can put this solution on YOUR website!There are 3 possible scenarios:
Scenario 1) Both roses are red
P(Both Red) = P(Red)*P(Red) = (3/12)*(2/6) = 6/72 = 1/12
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Scenario 2) Both roses are pink
P(Both Pink) = P(Pink)*P(Pink) = (4/12)*(2/6) = 8/72 = 1/9
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Scenario 2) Both roses are white
P(Both White) = P(White)*P(White) = (5/12)*(2/6) = 10/72 = 5/36
Now add up all the probabilities:
1/12 + 1/9 + 5/36 = 3/36 + 4/36 + 5/36 = (3+4+5)/36 = 12/36 = 1/3
So the probability that one rose chosen from each vase will be the same color is 1/3
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Equations/584904: m/9 - 7/18 =1
1 solutions
Answer 372963 by jim_thompson5910(28476) on 2012-03-09 15:27:10 (Show Source):
You can put this solution on YOUR website! Start with the given equation.
 Multiply both sides by the LCD  to clear any fractions.
 Distribute and multiply.
 Add  to both sides.
 Combine like terms on the right side.
 Divide both sides by  to isolate  .
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Answer:
So the solution is
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If you need more help, email me at jim_thompson5910@hotmail.com
Also, please consider visiting my website: http://www.freewebs.com/jimthompson5910/home.html and making a donation. Thank you
Jim
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Sequences-and-series/584884: Given a term in a arithmetic sequence and the common difference find the explicit formula
a12=30 d=6 1 solutions
Answer 372936 by jim_thompson5910(28476) on 2012-03-09 14:22:06 (Show Source):
You can put this solution on YOUR website!a[n] = a[1] + (n-1)d
a[12] = a[1] + (12-1)*6
30 = a[1] + (12-1)*6
30 = a[1] + 66
30-66 = a[1]
-36 = a[1]
a[1] = -36
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a[n] = a[1] + (n-1)d
a[n] = -36 + (n-1)6
a[n] = -36 + 6n-6
a[n] = 6n-42
So the explicit formula for the sequence is
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Probability-and-statistics/584876: Find the mean, variance,and binomial distribution with the given values of n and p.
n=122,p=0.24
The mean is: _____ (round to the nearest tenth as needed)
The variance is:_____(round to the nearest tenth as needed)
The standard divination is: _____(round to the nearest tenth as needed) 1 solutions
Answer 372932 by jim_thompson5910(28476) on 2012-03-09 14:04:59 (Show Source):
You can put this solution on YOUR website!Mean:
mu = np = 122*0.24 = 29.28
So the mean is 29.3 (rounded to the nearest tenth)
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Variance:
sigma^2 = np(1-p) = 122*0.24(1-0.24) = 22.2528
So the variance is 22.3 (rounded to the nearest tenth)
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Standard Deviation:
sigma = sqrt(np(1-p)) = sqrt(122*0.24(1-0.24)) = 4.717287
So the standard deviation is 4.7 (rounded to the nearest tenth)
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Probability-and-statistics/584875: Use the confidence interval to find the margin of error and the sample mean:
(0.256,0.380)
a.The margin of error is: _____
b.The sample mea is: _____ 1 solutions
Answer 372931 by jim_thompson5910(28476) on 2012-03-09 14:02:13 (Show Source):
You can put this solution on YOUR website!a)
The margin of error is equal to the radius of the confidence interval or half the width of the confidence interval.
Margin of Error:
ME = (b-a)/2, where the confidence interval is (a,b)
ME = (0.380-0.256)/2
ME = 0.062
So the margin of error is 0.062
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b)
The sample mean is the center of the confidence interval. Note: this is assuming that this is a confidence interval for the true population mean.
Sample Mean:
xbar = (a+b)/2, for some confidence interval (a,b)
xbar = (0.256 + 0.380)/2
xbar = 0.318
So the sample mean is 0.318
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Equations/584808: 10+x-(2-3x)=4 1 solutions
Answer 372920 by jim_thompson5910(28476) on 2012-03-09 12:52:32 (Show Source):
You can put this solution on YOUR website! Start with the given equation.
 Distribute.
 Combine like terms on the left side.
 Subtract  from both sides.
 Combine like terms on the right side.
 Divide both sides by  to isolate  .
 Reduce.
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Answer:
So the solution is
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