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scott8148 answered: 6619 problems
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A customer walks into an electronics store and buys five MP3 players and eight sets of headphones, paying $840. A second customer buys three MP3 players and four sets of headphones, and pays $480. How much does an MP3 player cost? How much does a set of headphones cost?
1 solutions
Answer 312282 by scott8148(6628)   on 2011-05-27 19:09:23 (Show Source):
You can put this solution on YOUR website!"five MP3 players and eight sets of headphones, paying $840" ___ 5m + 8h = 840
"three MP3 players and four sets of headphones, and pays $480" ___ 3m + 4h = 480
BIG HINT: multiply 2nd equation by 2 and subtract 1st equation
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Radicals/454514: How do you simplify this?
-5 sqrt(300)
I already did this:
-5 sqrt(25*12)
-5(5 sqrt (12))
But I don't know if that's right or, if it is right then would I split the 12 too?
1 solutions
Answer 312114 by scott8148(6628) on 2011-05-26 19:48:03 (Show Source):
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Polynomials-and-rational-expressions/451388: I am having trouble with solving rational equations! The problem is  . I have tried numerous ways of doing this problem, but when I get towards the end the factoring starts to confuse me. If you could show me step by step how to do this, I would be super thankful. Thanks so much!!
1 solutions
Answer 310391 by scott8148(6628) on 2011-05-18 20:06:31 (Show Source):
You can put this solution on YOUR website!multiplying by (n^2-1) ___ (3n)(n-1) = 12 + (n+4)(n+1) ___ 3n^2 - 3n = 12 + n^2 + 5n + 4
2n^2 - 8n - 16 = 0 ___ n^2 - 4n - 8 = 0 ___ NOT FACTORABLE
use the quadratic formula to find n
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Equations/450333: What am I doing wrong?
-5x-2[2x-4(x+7)]-6
Here is my work down.
-5x-2[2x-4(x+7)]-6
-5x-2[2x-4x+28]-6
-5x-4x-8x+56-6
-17x+50. I know that answer is wrong. But, why is the -8x not needed? Don't you distribute?
Thanks
1 solutions
Answer 309769 by scott8148(6628) on 2011-05-16 20:13:37 (Show Source):
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test/450159: There are 340 dinosaur model legs in a box. There are twice as many four legged dinosaur as there are two legged in the box. How many four legged dinosaur are there? And how many two legged dinosaur are there?
1 solutions
Answer 309705 by scott8148(6628) on 2011-05-16 16:24:09 (Show Source):
You can put this solution on YOUR website!"There are 340 dinosaur model legs in a box" ___ 4f + 2t = 340
"There are twice as many four legged dinosaur as there are two legged in the box" ___ f = 2t
solve the system of equations by substitution (or elimination)
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Graphs/450160: I need help writing an equation for a line parallel to 3y = -9x + 8, that passes through (-1, -4).
1 solutions
Answer 309703 by scott8148(6628) on 2011-05-16 16:17:29 (Show Source):
You can put this solution on YOUR website!parallel means the slope is the same, so the x and y coefficients don't change
the constant term (+8) should be different
to find the new constant term, plug in the coordinates of the point for x and y
3(-4) = -9(-1) + ? ___ -12 = 9 + ? ___ -21 = ?
the new equation is ___ 3y = -9x - 21
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Radicals/449755: hi, I am trying to help my child with homework and have forgotten how to solve radicals. Can you tell me the value of x in the following;
1.) Square root of x + 3 = 7
2.) Sq root of 2x + 5 = -6
3.) x divided by -3 = square root x +2
1 solutions
Answer 309361 by scott8148(6628) on 2011-05-15 19:38:42 (Show Source):
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Linear-equations/449518: Hi there,
I've been having some trouble understanding the directions to one of the problems in my worksheet:
For Problem's 21-40, first transform the equations so that either the x-coefficients or the y-coefficients are opposite. Then solve by the linear combination method.
I have provided number 21 to use as an example:
3x+5y=17
2x+3y=11
I have tried solving for x by multiplying each equation by the opposite of the x-coefficient. Ex: (2)3x+5y=17
(3)2x+3y=11
I wasn't sure if what I was doing was correct. Can you clarify? Thank you.
1 solutions
Answer 309357 by scott8148(6628) on 2011-05-15 19:33:36 (Show Source):
You can put this solution on YOUR website!you are on the right track
they want you to multiply by quantities so that either the x or y coefficients in the two equations will have the same values but opposite signs,
so they will be eliminated during linear combination (adding the equations)
just change one of your multiplication quantities to a negative (you won't always have to do this)
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logarithm/449753: OK so i need assistance with a logarithmic problem that is :
2log(base6)4-1/3log(base6)8= log(base6)X
I can't figure out how to get rid of the 2 and 1/3 from the equation so i can solve it
Thank you
1 solutions
Answer 309355 by scott8148(6628) on 2011-05-15 19:16:06 (Show Source):
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Quadratic_Equations/449500: Compute the discriminant of the quadratic equation 2x^2-3x – 5 = 0 and then
write a brief sentence describing the number and type of solutions for the
equation.
1 solutions
Answer 309354 by scott8148(6628) on 2011-05-15 19:13:01 (Show Source):
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Expressions-with-variables/449679: Hello:
I need help with the following word problem:
A university reported that its enrollment increased from 11,934 students in 2006 to 12,228 students in 2007.
a) What is the ratio of the number of students in 2007 to the number of students in 2006?
b) From the result in part a, determine the growth factor. Write it in deciomal form to the nearest thousandth.
c) By what percentage did the enrollment increase?
I believe the easy part is part a which I have determined to be 1.025. I am stumped by the rest.
Thank you so much for your help.
Julie
1 solutions
Answer 309348 by scott8148(6628) on 2011-05-15 19:01:48 (Show Source):
You can put this solution on YOUR website!you've already found the answers
b) sort of a trick question ___ the growth factor is equal to the ratio from a)
___ maybe the answer to a) is supposed to be the fraction, not the reduced decimal
c) the percentage is ___ (GF - 1) * 100 ___ OR ___ [(12228 - 11934) / 11934] * 100
___ it is the decimal portion of the growth factor
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Graphs/448704: Circle O has a center at (-1,1) and the line SL is tangent to circle O at S (-4,2). Write an equation for the line SL.
I believe that you have to find the slope. But after that?????
1 solutions
Answer 308723 by scott8148(6628) on 2011-05-12 18:16:48 (Show Source):
You can put this solution on YOUR website!a tangent is perpendicular to the radius at the point of tangency ___ SL is perpendicular to OS
find the slope and use point-slope to write an equation
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Linear-systems/448638: which equation reresents a line parallel to the line whose equation is 2y-5x=10
a.) 5y-2x=25
b.) 5y+2x=10
c.) 4y-10x=12
d.) 2y=10x=8
please & THANK YOU! (:
1 solutions
Answer 308713 by scott8148(6628) on 2011-05-12 17:53:53 (Show Source):
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Travel_Word_Problems/448674: Emily and Fran live 12 miles apart. Emily starts walking to Fran's house at a rate of 4 mph. Half an hour later, Fran starts jogging towards Emily's house at a rate of 6 mph. How long will Emily walk until she meets Fran?
If you can just show me how to set up the problem or how to put it into an equation i can work it out. I just dont know how to set it up! It would be great to have an answer by the end of the day :)
Thanks
1 solutions
Answer 308712 by scott8148(6628) on 2011-05-12 17:45:27 (Show Source):
You can put this solution on YOUR website!the distance Emily travels is her time multiplied by her rate
the distance Fran travels is Emily's time (minus half an hour) multiplied by Fran's rate
the two distances sum to 12 miles
equation-wise ___ t(4) + (t - .5)(6) = 12
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percentage/448651: Hi i have a question about my home work i have i am in &Th grade and am curently failing math in Pre-algebra. My question is to do with Percentages its "What percent of 91 is 45?" i need help working it out thanks!
1 solutions
Answer 308709 by scott8148(6628) on 2011-05-12 17:31:08 (Show Source):
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Travel_Word_Problems/448376: Two cars begin driving from the same point in the opposite directions. The first car travels at an average rate of 58 miles per hour. The second car drives 67 miles per hour. How many minutes will it take for the cars to be 100 miles apart?
I started this but I don't think it's right:
100/58+60=t
Your help is greatly appreciated!!
1 solutions
Answer 308527 by scott8148(6628) on 2011-05-11 21:55:52 (Show Source):
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Linear_Equations_And_Systems_Word_Problems/448194: The DVD Statistics show that the average person watches 48 DVD’s a year.
1.Write an equation to show the total number of DVD’s watched in one year. Use x for the number of action DVD’s and use y to represent the other categories.
X+y=48
The average person watches 3 times as many action DVD’s as any other category.
2.Write an equation to show the relationship between the action DVD’s and the other categories.
3x+y=48
This is what I came up with but it doesn't work out for one, and just doesn't seem right. I think my first answer is correct but the second part is not right.
1 solutions
Answer 308459 by scott8148(6628) on 2011-05-11 18:01:11 (Show Source):
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Linear-equations/447481: Given the points (26, 16) and (40, 26) how would I write an equation that correctly models the two points. I know its a linear equation and if this was on a roof I could tell you that the the pitch of the roof was about a 8/12, but just don't have any idea how to figure out an equation from two points for this college algebra class final project. Also its asking for a y intercept, but since we're dealing with positive numbers would there even be one? All help greatly appreciated.
1 solutions
Answer 308080 by scott8148(6628) on 2011-05-10 12:07:59 (Show Source):
You can put this solution on YOUR website!unless a line is vertical (which this one isn't) it has to cross the y-axis somewhere (y-intercept)
the slope of the line is defined as the "change in y", divided by the "change in x"
___ as you go from one point to the other, how much do the x and y values change?
___ divide the changes to find the slope
use the slope-intercept form of the equation to finish the solution
___ y = mx + b ___ m is the slope and b is the y-intercept
___ plug in your calculated slope value
___ plug in the coordinates of one of the points for the x and y values ___ then solve for the value of b (the y-intercept)
you now have the equation you need (y = mx + b) and the intercept is part of it
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Quadratic-relations-and-conic-sections/446870: The graph of a parabola of the form y = x2 + bx + c crosses the
y-axis at –36 and the x-axis at x = 3. At what other point does
the graph cross the x-axis?
A. x = –12
B. x = –9
C. x = 9
D. x = 12
The answer is A but im not sure how to arrive at that??????
1 solutions
Answer 307943 by scott8148(6628) on 2011-05-09 20:24:13 (Show Source):
You can put this solution on YOUR website!the y-intercept (when x=0) is -36, so this must be the value of c
___ -36 = 0^2 + b(0) + c
the x-intercept (when y=0) is 3
___ 0 = 3^2 + 3b - 36 ___ 27 = 3b ___ 9 = b
y = x^2 + 9x - 36
factoring ___ 0 = (x + 12)(x - 3)
x - 3 = 0 ___ x = 3 ___ this was given
x + 12 = 0 ___ x = -12
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Linear_Equations_And_Systems_Word_Problems/447027: A student ears $10 per hour for tutoring and $7 dollars per hour as a teacher's aid. Let x= number of hours each weeks spent tutoring and y=the number of hours each week spent as teacher's aid. Write the objective function that describes the total weekly earnings:
e=10x+7y correct?
for the 2nd part of the problem:
The student is bound by the following constraints:
a) to have enough time for studies the student can work no more than 20 hours a week
x+y <=20 correct?
b) The tutoring center requires that each tutor spend at least 3 hours a week tutoring.
3x+y <=20 correct?
c) The tutoring center requires that each tutor spend no more than eight hours a week tutoring?
No sure here.
Any help will be appreciated thanks
1 solutions
Answer 307898 by scott8148(6628) on 2011-05-09 18:49:27 (Show Source):
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Surface-area/447171: Hi, here is my geometry question:
Find the volume of a sphere whose surface area is 100 pi cm2
I tried and got 166.6 pi cm3 but i dont know if it is right.
Thank you som much for your time!
1 solutions
Answer 307890 by scott8148(6628) on 2011-05-09 18:20:49 (Show Source):
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Numbers_Word_Problems/447169: I'm having trouble with word problems. Here is the question.
Find two consecutive odd integers such that twice the greater is 17 more than the lesser.
I know that consecutive odd integers would be x, x+2. Help :) Thanks so much.
1 solutions
Answer 307889 by scott8148(6628) on 2011-05-09 18:18:35 (Show Source):
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Miscellaneous_Word_Problems/447167: Juan Valdez sells two types of coffee bean. The higher quality kind has 17% coffee and the ordinary kind has only 10% coffee. He gets an order for 50 tons of beans with 12% coffee. How much of each kind should he mix to get the desired percent?
I've tried (17x+10y)/2=13.5 - but that goes nowhere. Can you help me find the equation so I can solve the problem? Thanks
1 solutions
Answer 307888 by scott8148(6628) on 2011-05-09 18:16:33 (Show Source):
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Travel_Word_Problems/447136: "C leaves from home going 40 kilometers per hour (km/h). When C is 9 km from home, D starts after C from the same place, going 58 km/h. How long does it take for D to catch up with C?"
I know the formula is "d=r*t", but other than that I'm confused.
1 solutions
Answer 307887 by scott8148(6628) on 2011-05-09 18:13:47 (Show Source):
You can put this solution on YOUR website!a lot of info given, but just look at it logically
C has a 9 km head start
___ and D is catching up at 18 km/h (58 - 40)
so, how long to close the 9 km gap
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Exponential-and-logarithmic-functions/446668: 
I have figured out that the +2 is not (x+2) but -log(3x)+2. I know that the x-intercept for this logarithm is (9,0) and that this log graphs in Quadrant I with a vertical asymptote being the y-axis. The graph crosses into quadrant IV through point (9,0).
I am suppose to convert and plot this logarithm as an exponent. Then using the X,Y points I devise, invert and use to plot the logarithm.
I am not able to convert to an exponent as I do not know how to handle the +2. I can't seem to reverse engineer this using the points (9,0) either as the negative sign prevents this.
I'm pretty stuck. I would really love some kind of hints to solving this one.
Thank you so much for your time and expertise!!
1 solutions
Answer 307616 by scott8148(6628) on 2011-05-08 19:55:59 (Show Source):
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Equations/446639: Translate to an equation:
p $25 potted plants and s $20 shrubs total $300
Graph the equation and use the graph to determine three different combinations of potted plants and shrubs that total $300
How should I graph it? I don't really get it.
My answer (Is that correct?):
25p + 20s = 300
1 solutions
Answer 307590 by scott8148(6628) on 2011-05-08 18:04:00 (Show Source):
You can put this solution on YOUR website!your equation is good
draw a set of perpendicular axes, label one axis p and the other s
find the intercepts (by setting p and then s equal to zero in your equation) and mark them on the appropriate axes
the graph is the line connecting the intercepts ___ it should pass through several integer pairs for p and s
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Probability-and-statistics/446319: The correct answer for this problem is not 21. I need help with this difficult homework equation. Can someone please show me how to come up with the CORRECT answer?
Suppose the life of a certain brand of vacuum cleaner is normally distributed with a mean life of 12 years and a standard deviation of 4 years. A vacuum cleaner is randomly chosen.
10. (3 points) For how many years should the manufacturer warranty its vacuum cleaners if it is willing to replace only 1% of the vacuum cleaners it sells (Round answer to the closest whole number).
1 solutions
Answer 307584 by scott8148(6628) on 2011-05-08 17:30:00 (Show Source):
You can put this solution on YOUR website!this is a z-score problem ___ solve it using a table ___www.regentsprep.org/Regents/math/algtrig/.../ZChart.htm
the question is asking how many standard deviations below the mean represents the lowest 1% of the population
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Surface-area/446299: how would you find the lateral area of a cone with a length of 20 cm and the radius of 9 cm. i have got 9^2 + 20^2 = 481. than take the square root of 481, which is 21.93, but i don't know what to do after that?
1 solutions
Answer 307578 by scott8148(6628) on 2011-05-08 17:10:06 (Show Source):
You can put this solution on YOUR website!you found the slant height of the cone ___ this is the radius of the circle that the cone could be cut from
the LA of the cone is some fraction of the area of the circle
the fraction is the radius of the cone divided by the radius of the circle (which is the slant height of the cone)
LA = [9 / sqrt(481)] * pi * [sqrt(481)]^2
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