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Expressions-with-variables/447577: Solve for a specified variable
The formula P=B/1+s is used to determine what amount of principal P should be invested for 1 year at a simple interest rate in order to have B dollars after a year.
I wasn't sure whether I should put this here, or in money word problems. Sorry if I'm in the wrong place, but I'd be very relieved to have some help with this problem. 1 solutions
Answer 308096 by solver91311(17059) on 2011-05-10 13:24:50 (Show Source):
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Travel_Word_Problems/447163: Matt and Anna Killian are frequent fliers on fast-n-go airlines. They often fly between two cities that are a distance of 1680 miles apart. on one particular trip, they flew into the wind and the trip took 4 hours. The return trip with the wind behind them, only took about 3.5 hours. find the speed of the wind and the speed of the plane in still air 1 solutions
Answer 307916 by solver91311(17059) on 2011-05-09 19:27:23 (Show Source):
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Sequences-and-series/447147: For any integers n, let ® n be defined as the sum of the distinct prime factors of n. For instance, ® 36=5, because 2 and 3 are the only prime factors of 36 and
2+3=5.
What is the smallest value of w for which ® w=12 ?
1 solutions
Answer 307880 by solver91311(17059) on 2011-05-09 18:03:53 (Show Source):
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logarithm/445194: I am supposed to find how many words found after the time limit (t) here is the equation: L(t)=225(1-e^-0.0061t). I am supposed to find how, after 30min. and 60min., many words the student has learned. 1 solutions
Answer 306741 by solver91311(17059) on 2011-05-04 19:45:44 (Show Source):
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Surface-area/445182: A landscaper is preparing a circular flowerbed. The bed has a 12 - foot diameter. He will need 13 plants per square yard. How many plants should he buy?
AND HOW??
Thanks 1 solutions
Answer 306736 by solver91311(17059) on 2011-05-04 19:31:25 (Show Source):
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Triangles/445127: a flower bed is in the shape of a triangle with one side twice the length of the shortest side, and the third side is 25 feet more than the length of the shortest side. find the dimensions if the perimeter is 165 feet 1 solutions
Answer 306718 by solver91311(17059) on 2011-05-04 18:14:38 (Show Source):
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Permutations/445117: Could you please explain, 'How many combinations of three letters each can be made out of the following:'
ROYBGIV
ROYBGIV
ROYBGIV
Kind regards,
Rod Horton. 1 solutions
Answer 306716 by solver91311(17059) on 2011-05-04 18:11:40 (Show Source):
You can put this solution on YOUR website!
That depends on how you are using the word "Combination." In the strict mathematical sense it means how many different ways to choose groups where the order of elements in an individual group doesn't matter. Furthermore, elements are typically not repeated.
So, if ROY is a different combination than YRO or ORY, or if RRB is a valid choice, then you are using combination in a non-standard way. In such case, there are 7 ways to chose the first of the three times 7 ways to chose the second of the three times 7 ways to pick the third element, for a total of 343 different arrangements.
If order matters but you can't duplicate, then there are 7 ways to pick the first element, 6 ways to pick the second element, and 5 ways to pick the 3rd element for a total of 210 different arrangements.
However, the number of combinations (where order doesn't matter) of n things taken k at a time is given by:
So for 7 things taken 3 at a time:
Notice that this result is the previous result divided by 6, which, by the way is the number of ways that three different things can be arranged, for example ROY, RYO, YOR, YRO, OYR, ORY.
John

My calculator said it, I believe it, that settles it
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Graphs/445079: how would you graph the quadratic function y=xsquared-4x+2 1 solutions
Answer 306692 by solver91311(17059) on 2011-05-04 17:16:04 (Show Source):
You can put this solution on YOUR website!
The same way I would graph any quadratic function. Given the quadratic function:
I would first calculate the -coordinate of the vertex:
Then I would calculate the -coordinate of the vertex:
Then I would plot the vertex point:
Then I would plot the -intercept:
Then I would use the properties of symmetry to plot the point symmetric to the -intercept:
Then I would calculate the discriminant, .
If then I would know that there are no -intercepts. In this case I would select an integer value close to and calculate the function value at that independent variable value. I would repeat this step with different independent variable values as often as I felt necessary to give an indication of the shape of the curve.
If then I would know that I have already plotted the -intercept, namely the vertex. I would proceed to plot another couple points as in the situation described above.
If , then I would know that there are two distinct real roots and therefore two -intercepts. I would set the function equal to zero and solve the resulting quadratic equation by the most convenient means. Once I had determined the two values for the roots, and , I would plot the two points: and .
Generally speaking, that is sufficient to give an idea of the shape of the curve, so all that is left is to draw a smooth curve through all of your plotted points. If you are unsure of the curve's shape by this point, then by all means select some different values for the independent variable and calculate the function value to give yourself additional data points to use.
John

My calculator said it, I believe it, that settles it
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Quadratic_Equations/444975: During a chemistry experiement, the cork in a 0.5 foot tall beaker with an effervescent solution pops off with an initial velocity of 20 feet per second.
How many seconds does it take for the cork to hit the table? 1 solutions
Answer 306630 by solver91311(17059) on 2011-05-04 14:04:51 (Show Source):
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Equations/444628: May you please help me on this word promblem? : a chess tournament starts with 64 people commpeting. The ecponential function, y=64(1/2)^x describes how many people are remaining in the tournament after x rounds. how many rounds will it take to reach a champion?
1 solutions
Answer 306453 by solver91311(17059) on 2011-05-03 20:36:49 (Show Source):
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