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Mixture_Word_Problems/373434: $9500 is invested, part of it at 10% and part of it at 8%. For a certain year, the total yield is $878.00. How much was invested at each rate?
How much was invested at 10%?
How much was invested at 8%? 1 solutions
Answer 265786 by josmiceli(9649) on 2010-11-18 20:41:08 (Show Source):
You can put this solution on YOUR website!Let  = amount invested at 10%
Let  = amount invested at 8%
given:
(1)

(2) 
Multiply both sides of (1) by 
and subtract (1) from (2)
(2) 
(1)

and, since
(1)

$5,900 was invested at 10% and $3,600 was invested at 8%
check answer:

OK
|
Word_Problems_With_Coins/373028: if i have 20 coins only dimes and quarters and have $3.80 how many quters do i have 1 solutions
Answer 265613 by josmiceli(9649) on 2010-11-18 02:24:14 (Show Source):
You can put this solution on YOUR website!Let  = number of dimes
Let  = number of quarters
given:
(1) 
(2)  (in cents)
-------------------------------
Multiply both sides of (1) by
and subtract (1) from (2)
(2) 
(1)

And, from (1),

I have 8 dimes and 12 quarters
check answer:
(2) 
(2)

OK
|
Equations/373047: one canned juice drink is 20% orange juice; another is 5% orange juice. how many liters of each should be mixed together in order to get 15L that is 13% orange juice? 1 solutions
Answer 265611 by josmiceli(9649) on 2010-11-18 02:16:57 (Show Source):
You can put this solution on YOUR website!Let  = liters of 20% oj needed
Let  = liters of 5% oj needed
given:
(1) 
(2) 
-------------------------------------
From (2):
(2) 
(2) 
Multiply both sides of (1) by 
and subtract (1) from (2)
(2) 
(1)

And, from (1),

8 liters of 20% oj and 7 liters of 5% oj are needed
check the answer:
(2)

OK
|
Quadratic_Equations/372841: I have pulled my hair out trying to learn this stuff!! If anyone could help me I'd so appreciate it!! thank you!!
Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this.
3x + 11y = 34.5
9x – 7y = -16.5 1 solutions
Answer 265538 by josmiceli(9649) on 2010-11-17 19:38:17 (Show Source):
You can put this solution on YOUR website!It helps to get all the terminology straight,
otherwise, you can't talk about it
You have:
1st equation:
(term 1) + (term 2) = (term 3)
2nd equation:
(term 1) + (term 2) = (term 3)
What you are trying to do is
get either the (term 1)'s equal to each other
or the (term 2)'s equal to each other.
Then the next step is to multiply both sides
of equation 2 by -1
Then when add the equations, you get:
1st equation:
(term 1) + (term 2) = (term 3)
2nd equation:
-(term 1) - (term 2) = -(term 3)
So, you've gotten rid of either the (term 1)'s or the (term 2)'s
--------------
How do you get (term 1)'s equal to each other?

Multiply both sides of equation 1 by

Now you can multiply both sides of equation 2 by 
and add the equations
 (note that all the signs are changed)
Adding:

Divide both sides by

Now you can plug this result back into
either equation and find 
Does this help?
|
Finance/372802: A car rental company charges a daily rental fee plus a per mile fee over 150 miles. Two different people rent the same style of car for the same number of days. The total bill for one persons rental is $207.50 for a 5-day rental and 180 miles. The total bill for the other persons rental is $212.50 for a 5-day rental and 200 miles.
I need to write a linear system that I can use to find the daily rental fee and the per mile fee over 150 miles. 1 solutions
Answer 265527 by josmiceli(9649) on 2010-11-17 18:53:57 (Show Source):
You can put this solution on YOUR website!Let  = daily rental fee
Let  = the per mile fee over 150 miles
given:
Person 1: cost of daily rental = 
Person 2: cost of daily rental = 
Person 1: per mile fee over 150 miles = 
Person 2: per mile fee over 150 miles =
------------------

Multiply both sides of each equation by

Divide both sides of each equation by
|
Systems-of-equations/372765: A dehydrated patient needs a 2.6% saline IV. Unfortunately, the hospital only has bags of 8% and 2% saline solutions. How many liters of each solutions should be mixed together to yield 2 liters of the desired concentration. 1 solutions
Answer 265514 by josmiceli(9649) on 2010-11-17 18:20:20 (Show Source):
You can put this solution on YOUR website!Let  = liters of 8% solution needed
Let  = liters of 2% solution needed
In words:
(liters of saline)/(liters of solution) = 2.6%
(1) 
(2) 
------------------
From (1):
(1) 
(1) 
Multiply both sides of (2) by  and
subtract from (1)
(1) 
(2)

And, since

.2 liters of 8% solution and 1.8 liters of 2% solution are needed
check answer:
(1) 
(1) 
(1)

OK
|
test/368101: A fish was caught whose tail weighed 9 lb. Its head weighed as much as it's tail pluse half its body. Its body weighed as much as it's head and tail. What did the fish weigh? 1 solutions
Answer 262328 by josmiceli(9649) on 2010-11-08 19:51:38 (Show Source):
You can put this solution on YOUR website!Let  = weight of tail
Let  = weight of body
Let  = weight of head
given:

---------------
By substitution:

(1) 
and

(2) 
Subtract (2) from (1)
(1) 
(2)

And, since,

The fish weighed  pounds
check answer:

and

OK
|
Travel_Word_Problems/367292: Two joggers are running around an oval track in opposite directions. One jogger runs around the track in 56 seconds. They meet every 24 seconds. How mant seconds does it take the second jogger to run around the track? 1 solutions
Answer 261810 by josmiceli(9649) on 2010-11-07 16:03:58 (Show Source):
You can put this solution on YOUR website!Each jogger cuts down the distance between them as they jog.
They are always approaching each other at their combined speeds
Jogger #1 has a speed of (1 trip around)/56 sec
At the sum of their speeds, (1 trip around)/24 sec
Let  = speed of Jogger #2

Multiply both sides by

The 2nd Jogger takes 42 sec to go around track
|
Quadratic_Equations/366861: The number of tickets sold each day for an upcoming performance of handel's Messiah is givn by N(x)=-0.4x^2+10.4x+10 where x is the number of days since the concert was first announced. When will daily sales peak and how many tickets will be sold that day? Pleas show work Thank you 1 solutions
Answer 261552 by josmiceli(9649) on 2010-11-06 17:51:08 (Show Source):
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Age_Word_Problems/366640: Erica and Rachel are both 90 years old. Breena, on the other hand, is half again as old as she was when she was half again as old as she was when she lacked five years of being half as old as she is now. How old is Breena? 1 solutions
Answer 261451 by josmiceli(9649) on 2010-11-06 07:51:08 (Show Source):
You can put this solution on YOUR website!Let  = her age now
 = half as old as she is now
 = lacking 5 years of being half as old as she is now
 = half again as old as she was when she lacked
five years of being half as old as she is now.
 = half again as old as she was when she was
half again as old as she was when she lacked five years
of being half as old as she is now.
She is this age now, so

Breena is 90 also
|
Quadratic-relations-and-conic-sections/366722: Write the equation for the parabola which opens left, has its vertex on the origin, and passes through the point (-3/2),1) 1 solutions
Answer 261412 by josmiceli(9649) on 2010-11-06 01:10:12 (Show Source):
You can put this solution on YOUR website!It would be of the form 
If the vertex is at the origin, then I can write
 , so 
If it includes (-3/2,1),

(1) 
By symmetry, it must also pass through (-3/2,-1), so

(2) 
Add (1) and (2)

And, since
(1)

The equation is
|
Polynomials-and-rational-expressions/366571: Choose two trinomials from the list below to factor. Using complete sentences, explain how to factor each one. Be sure that the final factorization (or "answer") is a part of your explanation.
2x2 + 13x + 15
2x2 + 27x + 13
5x2 − 2x − 7
10x2 − 7x − 3
8x2 − 11x + 3
HELP PLEASE?? 1 solutions
Answer 261275 by josmiceli(9649) on 2010-11-05 16:13:44 (Show Source):
You can put this solution on YOUR website!The second one,  , can be solved by
careful inspection.
First I notice that  . I want to arrange
the factors so I get this result for the coefficient of
 accomplishes this.
---------------------------
For the 4th one,  , I try  and 
for the factors of  . Then I try  and 
for the factors of  . This gives me
 as the answer with  as the coefficient of
|
Mixture_Word_Problems/366493: Soybean meal is 14% protein; cormeal is 7% protein. How many pounds of each should be mixed together in order to get 280-lb mixture that is 11% protein?
How many pounds of the cornmeal should be in the mixture?
How many pounds of the soybean meal should be in the mixture? 1 solutions
Answer 261168 by josmiceli(9649) on 2010-11-05 09:57:25 (Show Source):
You can put this solution on YOUR website!Let  = pounds of cornmeal needed
Let  = pounds of soybean meal needed
given:
Pounds of protein in  pounds of cornmeal:

Pounds of protein in  pounds of soybean meal

(1) 
----------------
In words:
(pounds of protein in final mixture)/(total pounds of final mixture) = 11%

divide both sides by 
(2) 
Subtract (1) from ()
(2) 
(1)

and, since

120 pounds of cornmeal and 160 pounds of soybean meal are needed
check answer:

OK
|
Miscellaneous_Word_Problems/366383: A health clinic uses a solution of bleach to sterilize petri dishes in which cultures are grown. The sterilization tank contains 120 gal of a solution of 4% ordinary household bleach mixed with pure distilled water. New research indicates that the concentration of bleach should be 6% for complete sterilization. How much of the solution should be drained and replaced with bleach to increase the bleach content to the recommended level? 1 solutions
Answer 261079 by josmiceli(9649) on 2010-11-04 22:33:01 (Show Source):
You can put this solution on YOUR website!Let  = gallons of 4% solution to be drained
given:
Bleach in 4% solution:
 gal
Bleach in removed portion:

Gallons of bleach added:

----------
In words:
(initial gallons of bleach - bleach removed + bleach added)/(total gallons) = 6%

2.5 gallons of 4% solution must be drained
and replaced with pure bleach
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Numbers_Word_Problems/366367: I am a number between 70 and 100. My ones digit is 1 more than my tens digit. I am a prime number. What number am I? 1 solutions
Answer 261068 by josmiceli(9649) on 2010-11-04 21:56:50 (Show Source):
You can put this solution on YOUR website!I can eliminate 70, 100, 99, and 98, which all have divisors
So I'm left with 71 through 97
I can eliminate all numbers ending in 2,4,5,6, and 8, since they
all have divisors. That leaves number ending in 1,3,7, or 9
The tens digit has to be 7,8, or 9. If the ones digit is 1 more
than the tens digit, then the possible numbers are just one: 89
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Linear-equations/366319: Translate to an equation:
f $50 poker chips and t $20 poker chips total $400
Determine three different combinations of $50 poker chips and $20 poker chips that total $400 1 solutions
Answer 261044 by josmiceli(9649) on 2010-11-04 21:22:47 (Show Source):
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