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all answered: 49 problems
Jump to solutions: 0..29 , 30..59, >>NextFinance/241251: i do not understant how to answer this question could i get help please. i need to determine how many years it will take for the two accounts to reach the same balance. 1000 investment with a rate of 5.25% compounded continuously and 800 investment with a rate of 6.25% compounded continously. i got this far
1000e^.0525=800e^.0625 1 solutions
Answer 176653 by Alan3354(6054) on 2009-11-20 20:49:57 (Show Source):
You can put this solution on YOUR website!how many years it will take for the two accounts to reach the same balance. 1000 investment with a rate of 5.25% compounded continuously and 800 investment with a rate of 6.25% compounded continously. i got this far
1000e^.0525=800e^.0625
----------------------
1000e^.0525t=800e^.0625t You need the time in the exponents
--------------
Take the ln of both sides
ln(1000) + 0.0525t = ln(800) + 0.0625t
0.0625t - 0.0525t = ln(1000) - ln(800)
0.01t =~ 0.223144
t =~ 22.3144 years (assuming the int rates are annual)
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Polynomials-and-rational-expressions/241220: Perform the indicated operations and simplify.
x^2/3x^2-5x-2-2x/3x+1∙1/(x-2) 2 solutions
Answer 176651 by jsmallt9(590) on 2009-11-20 20:05:04 (Show Source):
You can put this solution on YOUR website!(Note: A solution provided by another tutor has some very serious errors in it. The solution is not correct. The first part was correct. You do want to factor the denominators, use the factored denominators to find the lcd and you do want to write each fraction with the lcd for the denominator. But after that it goes very wrong. This is where I will start.)

lcd: 
To avoid some common errors with subtractions, I am going to rewrite the expression as additions:

The first fraction already has the lcd as a denominator. The denominator of the second fraction is missing (x-2) so we will multiply its numerator and denominator by (x-2). The denominator of the third fraction is missing (3x+1) so we will multiply its numerator and denominator by (3x+1):

Multiply out the numerators but leave the denominators factored for now:

Now that the denominators are the same we can add:

At this point we should try to reduce the fraction. To reduce the fraction we have to factor the numerator and denominator. (We didn't multiply out the denominator earlier so that we would not have to factor it again now.) The only factoring that can be done on the numerator, however, is to factor out a -1:

As we can see, there are no common factors to cancel. So all we can do is simplify (i.e. multiply out):
Answer 176641 by stanbon(26252) on 2009-11-20 19:12:14 (Show Source):
You can put this solution on YOUR website!Perform the indicated operations and simplify.
[x^2/3x^2-5x-2]-[2x/3x+1]∙[1/(x-2)]
-----------------------------
Factor where you can:
[x^2/(x-2)(3x+1]-[2x/3x+1]∙[1/(x-2)]
---
lcd = (x-2)(3x+1)
---------------------------
Write each fraction with the lcd as its denominator:
[x^2/lcd] - [2x/lcd]
----
Combine the numerators over the lcd:
(x^2-2x]/[(x-2)(3x+1)]
---
(x(x-2))/[(x-2)(3x+1)]
---
x/(3x+1)
=================
Cheers,
Stan H.
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Angles/241230: two angles are supplementary. The measure of the larger angle is 36 degrees more the 7 times the measure of the smaller angle. Find the measures of both angles. 1 solutions
Answer 176650 by unlockmath(108) on 2009-11-20 19:58:44 (Show Source):
You can put this solution on YOUR website!Hello,
The wording of the problem seems but let's see what I can to help you. Let x represent the smaller angle and 7x+36 be the larger angle. We know supplementary s 180 degrees.
so here's the equation we can set up.
7x+36+x=180 Combine like terms:
8x+36=180 Subtract 36 from both sides gives us:
8x=144 Now divide both sides by 8 gives us:
x=18 So now we know the smaller angle is 18 degrees.
The larger angle is 162 degrees.
RJ Toftness
www.math-unlock.com
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Exponents-negative-and-fractional/240338: (9/8)^-2 the 9/8 is of course a fraction and the ^-2 is for a negative exponent. I dont get these. 1 solutions
Answer 176649 by Alan3354(6054) on 2009-11-20 19:38:01 (Show Source):
You can put this solution on YOUR website!(9/8)^-2
----------
= (9/8)^-2/1
It's a fraction. Multiply NUM and DEN by (9/8)^2
= (9/8)^0/(9/8)^2
= 1/(9/8)^2 anything with exponent 0 = 1
--------------
Moving a term from NUM to DEN (or v.v.) changes the sign of the exponent.
(9/8)^-2 = 1/(9/8)^2
1/(9/8)^2 = (1/(9/8)^2 = (8/9)^2
1 over a fraction is the inverse of the fraction.
= 64/81
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Graphs/241225: when doing systems of equations and graphing, i have a problem that reads
4x - 20 = 5y
8x - 10y = 12
i know how to graph the first equation but how do i graph the second equation? i was told by my instructor to solve using the intercept points by substuting the exponent with zero (4 * 0) - 20 = 5y and solve then sub zero for the other exponent and then graph the line but with the second equation the numbers come out in fraction form and i can not figure out how to graph the intercepts. any and all help would be appreciated...
thanks... 1 solutions
Answer 176648 by stanbon(26252) on 2009-11-20 19:37:16 (Show Source):
You can put this solution on YOUR website!when doing systems of equations and graphing, i have a problem that reads
4x - 20 = 5y
8x - 10y = 12
--------------------------
Solve each for "y"
y = (-4/5)x - 4
Plot points: (0,-4)(5,0)

-----------------------------------------------
y = (4/5)x-(6/5)
Plot points: (-1,-2)(4,2)

--------------------------
Both together:

====================================
Cheers,
Stan H.
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Equations/240985: three times one number plus -7 times another number equals 21 1 solutions
Answer 176647 by ankor@dixie-net.com(6689) on 2009-11-20 19:36:21 (Show Source):
You can put this solution on YOUR website!three times one number plus -7 times another number equals 21
:
3x + -7y = 21
:
3x - 7y = 21
:
-7y = -3x + 21
:
Multiply by -1
7y = 3x - 21
:
y =  x - 
y =  x - 3
:
Some integer values, ignoring 0;
x=14, y=3
x=21 y=6
x=28 y=9
x=35 y=12
note as x increases by 7, y increase by 3
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test/240333: 2/5 = 5/10n + 2????????????????
The second one is: 7/10 = 3/8k + 1???????????????? 1 solutions
Answer 176646 by Alan3354(6054) on 2009-11-20 19:31:54 (Show Source):
You can put this solution on YOUR website!2/5 = 5/10n + 2
Do you want to solve for n? You didn't say.
Multiply thru (all terms) by 10 n
4n = 4 + 20n
0 = 4 + 16n
16n = -4
n = -1/4
---------
The second one is: 7/10 = 3/8k + 1
Multiply by 40k
28 = 15 + 40k
40k = 13
k = 13/40
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Trigonometry-basics/241174: I think my problem with these kinds of questions is that I’m having a hard time manipulating the secant, cosine, and so on. For instance, when trying to find the exact value for ‘sec 5π/12’; I know that sec=1/cos and I believe that I’m pretty much set up to use a sum difference identity but don’t think that I can just ...safetly assume that 1/cos=cos and I don’t know if I can honestly say how to change 1/cos into cos so I can use the identity. Also, I want to try my best to finish the rest on my own (that’s why I picked only one question). If anyone has any tips on handling Trig indentities and Trigonometry in general, I’d appreciate the advice. Thanks! ^_^ 1 solutions
Answer 176644 by jsmallt9(590) on 2009-11-20 19:26:53 (Show Source):
You can put this solution on YOUR website!Whenever a Trig problem refers to "exact values" you will end up using angles that are multiples of 30 or 45 degrees (or  or  radians).
Since you are looking for the exact value of  we have to find a way to express  in terms of multiples of  and/or  . This expression can be a sum or a difference. The expression can be twice or half a special angle. And this expression can be some combination of any of these.
So what expression of multiples of  and/or  equals  ? There are probably others but the one that is most obvious to me is:  . SO we will be using half-angle formulas.
There is no half-angle formula for sec, so we will find  and then find its reciprocal to get the sec:

(The  formula has a "+-" in front of the square root. However, since  ,  is in the first quadrant. And since  is in the first quadrant where all Trig functions are positive, we will discard the "-" and use the positive square root.)
Now we just find  , substitute and simplify.  is in the second quadrant where cos is negative. And its reference angle is  . Together this makes  . Substituting this into our equation we get:

To simplify this we will start by eliminating the fraction within a fraction. We can do this my multiplying the numerator and denominator of the "big" fraction by the LCD of the "little" fraction(s). Since there is only one "little" fraction, we will use its denominator, 2:

which simplifies to:

Using the property,  :

which simplifies to:

Now we can find the sec by finding the reciprocal of cos:

This may be an acceptable answer. However, the denominator is not rational. If you want rationalized denominators:

I'll leave it up to you to multiply this out.
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Finance/240975: A 67,500 estate is to be split amoung four children and a grandchildren. Each children gets the same amount and the grandchild gets half the amount. How much will each recevie? 1 solutions
Answer 176643 by ankor@dixie-net.com(6689) on 2009-11-20 19:24:24 (Show Source):
You can put this solution on YOUR website!Assume it should read:
A 67,500 estate is to be split among four children and a grandchild.
Each child gets the same amount, and the grandchild gets half the amount.
How much will each receive?
:
Let x = amt received by the grandchild
then
2x = amt received by the children
:
x + 4(2x) = 67500
x + 8x = 67500
9x = 67500
x = 
x = $7500 received by the grandchild
then
2(7500) = $15000 received the the children
:
:
Check 4(15000) + 7500 = 67500
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Mixture_Word_Problems/241134: To estimate the size of the bear
population on the Keweenaw Peninsula, conservationists
captured, tagged, and released 50 bears. One year later, a
random sample of 100 bears included only 2 tagged bears.
What is the conservationist’s estimate of the size of the
bear population?
1 solutions
Answer 176642 by ankor@dixie-net.com(6689) on 2009-11-20 19:15:03 (Show Source):
You can put this solution on YOUR website! To estimate the size of the bear population on the Keweenaw Peninsula,
conservationists captured, tagged, and released 50 bears.
One year later, a random sample of 100 bears included only 2 tagged bears.
What is the conservationist’s estimate of the size of the bear population?
:
let x = estimation of no. of bears
;
 = 
cross multiply
2x = 100 * 50
2x = 5000
x = 2500 bears
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Linear-equations/240330: Hello,
I have several things that I need help with. I need to see all of the steps to help me work future problems out. I am grateful for your help! This algebra has been mind boggling after being out of school for 32 years.
1. Graph the equations by completing the tables and plotting the points. You may use Excel or another web-based graphing utility.
a). y = -½ x + 3
Use the table; find at least 3 points using any values for x.
x y
-2
0
4
b). Use the values of x provided in the table.
x y
0
1
2
3
4
2. The cost function for the Recklus Hang gliding Service is C(x) = 0.4x2 - fx + m, where f represents the average fuel cost for a customer’s daily excursion and m represents the monthly hanger rental. Also, C represents the monthly cost in dollars of the small business where x is the number of flight excursions facilitated in that month.
a). If $60 is estimated to be the average fuels cost (f), and the monthly hanger rental is $3,000; write an equation for the profit, P, in terms of x.
Typing hint: Type x-squared as x^2
b).What is the cost when 40 flight excursions are sold in a month?
c). How many flight excursions must be sold in order to minimize the cost? Show your work algebraically. Trial and error is not an appropriate method of solution – use methods taught in class.
d). What is the minimum cost?
Thanks so much for helping me. I am taking this class on-line and I am having problems grasping this subject.
Best Regards,
1 solutions
Answer 176639 by Alan3354(6054) on 2009-11-20 19:05:09 (Show Source):
You can put this solution on YOUR website!1. Graph the equations by completing the tables and plotting the points. You may use Excel or another web-based graphing utility.
a). y = -½ x + 3
Use the table; find at least 3 points using any values for x.
Sub each x and find y
x....y
-2...4 --> (-2,4)
0....3 --> (0,3)
4....1 --> (4,1)
Plot the points and draw a straight line thru them.
------------------
b). Use the values of x provided in the table.
Is this the same equation?
x y
0 3
1 2.5
2 2
3 1.5
4 1
----------
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Probability-and-statistics/241210: the probability that 2 men in a group of 5 will still be working in 30 years is 3.5
What is the probability that 3 men in a group of 5 will still be working in 30 years?
can you also provide the formula with the answer?
thanks 1 solutions
Answer 176638 by stanbon(26252) on 2009-11-20 19:01:24 (Show Source):
You can put this solution on YOUR website!the probability that 2 men in a group of 5 will still be working in 30 years is 3.5
------
The probability cannot be 3.5. Probabilities are always between 0 and 1.
Cheers,
Stan H.
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Polynomials-and-rational-expressions/241131: Solve. (This one is really hard!)
3a-5/a^2+4a+3 + 2a+2/a+3 = a-3/a+1 1 solutions
Answer 176637 by ankor@dixie-net.com(6689) on 2009-11-20 19:01:19 (Show Source):
You can put this solution on YOUR website! +  = 
do some factoring here
 +  = 
The common denominator is (a+3)(a+1) multiply thru by this
:
(a+3)(a+1)*  + (a+3)(a+1)*  = (a+3)(a+1)* 
:
Cancel out the denominators, leaving:
(3a - 5) + (a+1)*2(a+1) = (a+3)(a-3)
:
FOIL
3a - 5 + 2(a^2 + 2a+ 1) = a^2 + 3a - 3a - 9
:
3a - 5 + 2a^2 + 4a + 2 = a^2 - 9
:
combine like terms on the left
2a^2 - a^2 + 3a + 4a - 5 + 2 + 9 = 0
:
a^2 + 7a + 6 = 0
Factor
(a + 6)(a + 1) = 0
Two solutions
a = -6
a = -1
;
:
Check in original equation using x=-6
 +  =
 +  =
 +  =
 +  =  ; confirms our solution
;
:
You can check it using x=-1
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Angles/241215: The second angle of a triangle is 30(degrees)less than the first angle.The third angle is twice the second angle. How large are the angles? This problem i really struggled on because i dont know how to write it out and solve it. 1 solutions
Answer 176636 by Alan3354(6054) on 2009-11-20 18:59:22 (Show Source):
You can put this solution on YOUR website!The second angle of a triangle is 30(degrees)less than the first angle.The third angle is twice the second angle. How large are the angles? This problem i really struggled on because i dont know how to write it out and solve it.
-------------
The 1st angle is d degrees
The 2nd angle is d - 30
The 3rd angle is 2*(d-30)
---------------
The sum is (always) 180º
d + d-30 + 2(d-30) = 180
4d - 90 = 180
4d = 270
d = 67.5º
2nd angle = 37.5º
3rd angle = 75º
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Triangles/241181: Hello.
I am doing a geometry problem and I have to find the measure of the sides and classify each triangle by its side.
But.. one of the coordinates/points are a radical . for example.
A(0,5) B(5 radical 3,2)
How can I solve this problem with the radical in it ?
Thank You 1 solutions
Answer 176634 by solver91311(5072) on 2009-11-20 18:35:48 (Show Source):
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Expressions-with-variables/241203: Intermediate Algebra
Find the slope,if possible,of the line passing through each pair of points.
(2,-1)and(6,3)
(4,0)and(3.8,2)
(3,9)and(7,15) 1 solutions
Answer 176633 by Alan3354(6054) on 2009-11-20 18:17:01 (Show Source):
You can put this solution on YOUR website!Find the slope,if possible,of the line passing through each pair of points.
(2,-1)and(6,3)
-------------
The slope, m, is the diff in y over the diff in x
m = (-1-3)/(2-6)
m = -4/-4
m = 1
------
You try the other 2, email me to check your work or for assistance at
gsihoutx@aol.com
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Pythagorean-theorem/241197: Can someone please tell me how to find the dimensions of a box that has a volume of 504 cubic inches and its sides measure x, x+1 and x+2. Much appreciated! 2 solutions
Answer 176632 by solver91311(5072) on 2009-11-20 17:49:06 (Show Source):
Answer 176630 by Alan3354(6054) on 2009-11-20 17:40:05 (Show Source):
You can put this solution on YOUR website!x*(x+1)*(x+2) = 504

It's likely to be integers, so look for integer roots.
504 = 2*2*2*3*3*7 so it's likely a root will be 7 or a multiple of 7. Plus, the dimensions are 3 sequential numbers.
504 = 7*8*9, so that's the answer.
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Geometry_Word_Problems/241152: A cylindrical container has 3 inches of water in it and is being filled at a rate of 1/2 inch per minute. The volume, V, of the water in the container is given by the function: V(h)=(π/4)h^3. Write a formula for the volume in terms of the time in minutes. Then, calculate the ammount of time that will take to fill the container to 70 cubic inches.
please.....help!!!!! i have been working from 2 hours!!!!!
and also (π = pi)mathematic pi. 1 solutions
Answer 176631 by ankor@dixie-net.com(6689) on 2009-11-20 17:41:06 (Show Source):
You can put this solution on YOUR website!A cylindrical container has 3 inches of water in it and is being filled at a rate of 1/2 inch per minute.
The volume, V, of the water in the container is given by the function: V(h)=(π/4)h^3.
Write a formula for the volume in terms of the time in minutes.
:
The formula appears to be the volume of a cylinder with a radius of 1/2 inch
V(h) = 
which is
V(h) = 
or
V(h) = 
:
let t = time in minutes, h = 3 inches to start with, therefore the height:
(3+.5t)
V(t) = 
:
Then, calculate the amount of time that will take to fill the container to 70 cubic inches.
Replace V(t) with 70, solve for t
 = 70
Multiply both sides by  (reciprocal gets rid of  on the left)
3 + .5t = 70 * 
:
3 + .5t = 
3 + .5t = 89.126
.5t = 89.126 - 3
.5t = 86.126
t = 
t = 172.25 min to reach 70 cu/inches
;
:
Check this in the volume equation: t=172.25
V(t) = 
V(t) = 
V(t) = 
V(t) = 69.9986 ~ 70
;
:
Two hrs is a long time, hope this has helped!
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Trigonometry-basics/241096: PLEASE HELP ME SOLVE THIS CIRCULAR FUNCTION:
theta is a angle is standard position with T(-20,-21)on its terminal ray.Find csc theta. THIS ARE THE POSSIBLE ANSWERS:
a)-29/20
b)29/20
c)-29/21 1 solutions
Answer 176629 by Alan3354(6054) on 2009-11-20 17:33:30 (Show Source):
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Angles/241142: The ratio of the measure of two complimentary angles is 1:5. What are the measures of the angles? 1 solutions
Answer 176627 by rfer(2683) on 2009-11-20 17:29:41 (Show Source):
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Rate-of-work-word-problems/240752: One good use for rational equations is the shared work problem. This solution would be of great help in scheduling employees. For example, If Bob can mow a lawn in 3 hours and Joe can do it in 5 hours, how long would it take them together? Some people would be tempted to just average the two values and get the answer of four hours, but that would be wrong since Bob can do it by himself in 3 hours.
Solve this word problem using rational equations.
What is the relation of the shared work problem to the following problem?:
I am filling my pool with two hoses. The larger hose can fill the pool by itself in 10 hours, The smaller hose can fill the pool in 15 hours. Unfortunately, I left the drain open in the pool and it can drain the pool in 20 hours. How long will it take before the pool is filled with both hoses running and the drain open?
2 solutions
Answer 176622 by Alan3354(6054) on 2009-11-20 17:15:39 (Show Source):
You can put this solution on YOUR website!For example, If Bob can mow a lawn in 3 hours and Joe can do it in 5 hours, how long would it take them together?
----------------
Use the shortcut, product/sum
3*5/(3+5) = 15/8
Answer 176613 by ankor@dixie-net.com(6689) on 2009-11-20 16:09:23 (Show Source):
You can put this solution on YOUR website!If Bob can mow a lawn in 3 hours and Joe can do it in 5 hours, how long would it take them together?
:
Let t = time required when they work together (assuming two lawn mowers)
let the completed job = 1
:
 +  = 1
clear the denominators, multiply by 15:
15*  + 15*  = 15(1)
cancel the denominators:
5t + 3t = 15
8t = 15
t = 
t = 1.875 hrs or 1 + .875(60) = 1 hr 52.5 min
;
:
Check solution in the original shared work equation:
1.875/3 + 1.875/5 =
.625 + .375 = 1
:
:
:
The larger hose can fill the pool by itself in 10 hours,
The smaller hose can fill the pool in 15 hours.
Unfortunately, I left the drain open in the pool and it can drain the pool in 20 hours.
How long will it take before the pool is filled with both hoses running and the drain open
:
Let t = time required to fill the pool with this situation
Let the full pool = 1
Use + for filling and - for draining
:
 +  -  = 1
Clear the denominator by multiplying by 60
:
Use the 1st one as an example, you should be able to do this by yourself.
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