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Recent problems solved by 'mathie123'
mathie123 answered: 224 problems
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Money_Word_Problems/609561: I am needing assistance in solving the following word problem. Amy paid $64.34 for a pair of shoes during a 15% off sale. What was the regular price? I have been trying to solve it. I do not think I am solving it the correct way. 1 solutions
Answer 383787 by mathie123(224) on 2012-05-10 13:35:05 (Show Source):
You can put this solution on YOUR website!So she paid 100%-15% of the regular price (85% of the regular price)
Let's call p our regular price. We can make the equation:
0.85*p=64.34
Now all we need to do is solve for p and we have our answer.
Let me know if this helps, or if there is still anything you are unsure about.
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Graphs/609566: Find three ordered pairs that satisfy the equation.
y = x+8 1 solutions
Answer 383785 by mathie123(224) on 2012-05-10 13:33:22 (Show Source):
You can put this solution on YOUR website!For this question, you can substitute any value for x and solve for the corresponding y:
For example, one order pair would be :
x=1
y=1+8=9
So we get the ordered pair (1,9).
As long as the two numbers satisfy the equation, they are an ordered pair on that line (remember that ordered pairs are written (x,y) )
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Geometry_Word_Problems/606682: A house stands next to a shed. The shed is 12 feet high and casts a shadow of 9 feet. At the same time, the house casts a shadow of 18 feet. How high is the top of the house? 1 solutions
Answer 382165 by mathie123(224) on 2012-05-03 10:28:40 (Show Source):
You can put this solution on YOUR website!These triangles are similar. Since the bases of the two triangles are doubled from the smaller to the larger, similarily, the heights will be doubled (giving us 2*12=24).
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Trigonometry-basics/606182: Given t= pi/3 , show that sin t csc t= 1. Write answers in fractional form. 1 solutions
Answer 381983 by mathie123(224) on 2012-05-02 10:30:42 (Show Source):
You can put this solution on YOUR website!For this question that holds not only for that t but for all t.
We know that csct=1/sint from definition of csc
So sint*csct=sint*(1/sint)=1 (assuming that sint does not equal 0, for pi/3 this is true).
Hopefully this helps:)
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Travel_Word_Problems/606241: If you run the mile at a pace of ten miles per hour what would your time be when you finish the race? 1 solutions
Answer 381979 by mathie123(224) on 2012-05-02 10:23:49 (Show Source):
You can put this solution on YOUR website!If I run a mile at a speed of ten miles per hour, it takes me 1/10 of the hour to run the mile.
Well, in an hour there are 60 minutes and 1/10*60=6
This means it will take me 6 minutes to run the mile.
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Money_Word_Problems/606235: What is the final balance for the investment? $1500 for 3 years at 10% compounded annually 1 solutions
Answer 381978 by mathie123(224) on 2012-05-02 10:22:34 (Show Source):
You can put this solution on YOUR website!The formula for compound interest is :

where FV represents the future value, PV represents the present value (how much you put into the account right now), i represents the interest rate per period and n represents the number of periods (in our case years).
So we have PV=1500
n=3
and i=0.1 (which is the same as 10%)
Substituting this into our formula we have:
You need to solve for FV (I will let you do the rest- let me know if you are unsure about anything:)
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Triangles/606236: What is the approximate measure of 1 solutions
Answer 381976 by mathie123(224) on 2012-05-02 10:15:55 (Show Source):
You can put this solution on YOUR website!Is this a triangle (Perhaps a right-angled triangle?) We just need a little bit more information to help you with this one so anything else you could tell us about the question would be wonderful:)
Even the fact that it is a scalene triangle doesn't help us quite enough -- does on the of angles have a box on it (a right angle)? Or are we given any other angles maybe?
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Trigonometry-basics/606196: trigonometry equations
please help me solve this
3tan^2x+4tanx-4=0 1 solutions
Answer 381966 by mathie123(224) on 2012-05-02 09:57:07 (Show Source):
You can put this solution on YOUR website!This is just a quadratic with a twist. (I will help you get started, however you will have to try it yourself to get the answer)
Instead of x in our polynomial we have tanx.
We have dealt with solving for x in quadratics before (If you have been given this question- I hope you have- if not check out factoring/quadratic equations)
Instead of solving for x however you are solving for tanx
And finally, once you have solved for tanx, you have tools to solve for x (tan inverse, or perhaps a special triangle).
Try it out and see if this puts you on the right track if you are still confused let me know:)
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Expressions-with-variables/606194: Graph the inequality on a plane.
 1 solutions
Answer 381964 by mathie123(224) on 2012-05-02 09:53:40 (Show Source):
You can put this solution on YOUR website!
For now, let's just look at the following equation:

we can make this into a more familiar line:
and using the slope and y intercept of this line we can graph it (I will let this up to you, remembering that we have the point (0,-4) from the b value and the slope is -4=rise/run=-4/1)
Now, once you have graphed the line you will have broken your plane into two regions. take any point from each region (but not on the line) and test them. By test I mean plug into:

and see if it holds true, if so, shade the region, if not, leave the region unshaded.
Hopefully this helps get you on the right track:)
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Mixture_Word_Problems/606225: how much pure acid should be mixed with 5 gallons of a 40% acid solution in order to get a 50% acid solution? 1 solutions
Answer 381959 by mathie123(224) on 2012-05-02 09:43:16 (Show Source):
You can put this solution on YOUR website!Pure acid-- this means that we have 100% acid
Using that fact:
we have the following equation:
where x is the amount of pure acid that is added (also note that we will end up with x+5 gallons in the end)
From here it is a matter of algebra and solving for x.
try it yourself from this step, and let me know if you have any difficulties:)
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Travel_Word_Problems/606222: john drove home at 40 mph. average speed on return is 24mph. return trip took 1/2 hour longer because of traffic. how for did she travel to appointment 1 solutions
Answer 381955 by mathie123(224) on 2012-05-02 09:35:29 (Show Source):
You can put this solution on YOUR website!For these types of questions, I find it useful to make a table that compares the way there vs the way back (speed, distance and time).
We also need to recall that speed=distance/time
Okay, so for the way there we drove at 24 mph. We do not know the distance so I will call it d. and similarily we do not know the time. I will call the time y.
For the way back we drove at 40 mph a distance of d and a time of y-0.5.
Using our speed equation we know that distance=speed*time (just rearranging it).
Now we can make equations using what we have:
For the trip there:

and the way back:
Now I will let you do the rest. You have two equations with two unknowns (d and y). We just need to find d.
Try it out and if you are still not able to get the answer let me know:)
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Rectangles/606207: What are length and width of rectangle with an area of 59 square units? What is perimeter? 1 solutions
Answer 381951 by mathie123(224) on 2012-05-02 09:22:59 (Show Source):
You can put this solution on YOUR website!This has MANY answers....
We know that the area of a rectangle is
So we have:

But we can substitute in any number for L and get a corresponding W. (If it was a square however, there would only be one answer as we substitute L=W and solve for W.
With the perimeter the same problem remains. Once we have a L and W we have:

But due to the fact that there are many such L and W, there are just as many perimeters.
Hopefully this clears things up a bit, if there was any more specifications with the question Let me know so I can be more clear with my answer.
Okay, using the new information, if we want the smallest rectangle with whole number lengths and widths-- we know that the smallest length we can have is 1 making the width 59 (not that this is smaller perimeter than if we had a square with area 59 and any other rectangles with that area with whole number lengths).
From here, you can use the above formula and find perimeter. :)
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Percentage-and-ratio-word-problems/606217: A person's annual salary is $80,000. A percentage of 10.25% is deducted from the salary for the person's retirement plan.
After deducting the cost of the retirement plan, approximately how much money remains from the annual salary? 1 solutions
Answer 381950 by mathie123(224) on 2012-05-02 09:18:51 (Show Source):
You can put this solution on YOUR website!So we started with a salary of 80 000. Since 10.25% was deducted, (and the original amount is 100%), we have
 remaining
So that means we have

remaining in the annual salary. Hopefully this helps a bit:) If you are unsure about anything let me know:)
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Probability-and-statistics/605788: Laura will compute the mean of 3 numbers and express her answer to 2 decimal places. For which set of numbers will her answer be exact?
A.
{12, 31, 42}
B.
{15, 30, 40}
C.
{17, 31, 45}
D.
{18, 36, 50}
1 solutions
Answer 381805 by mathie123(224) on 2012-05-01 11:55:28 (Show Source):
You can put this solution on YOUR website!For this one, you will have to compute the mean of each set of 3 numbers and see which sets have exactly two decimal places (or none or 1 as we can add a 0 onto it eg. 1=1.00)
I will do A for you and let you do the others.
mean of A= 
=
So that one is NOT one of the number sets the work.
Try the rest out and let me know if you have any problems:)
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