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Recent problems solved by 'josmiceli'

josmiceli answered: 3007 problems
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Equations/241368: Perform the indicated operation. thanks
(42k^3 + 12^k2 + 18k) ÷ (6k)
1 solutions

Answer 176775 by josmiceli(3007) About Me  on 2009-11-21 13:05:53 (Show Source):


Equations/241367: Factor completely. If the polynomial is prime, state this. thanks
48x^2 + 40xy - 48y^2
1 solutions

Answer 176771 by josmiceli(3007) About Me  on 2009-11-21 13:00:35 (Show Source):
You can put this solution on YOUR website!



I did it by trial & error


Money_Word_Problems/241324: 1. Sajid has a goal of saving $20 000 in 8 years. What principal invested for 5 years at 6% per annum, compounded semi-annually, then for the next 3 years at 6.5%/a, compounded quarterly, would achieve this goal?


1 solutions

Answer 176766 by josmiceli(3007) About Me  on 2009-11-21 12:49:23 (Show Source):
You can put this solution on YOUR website!
The formula is

For 5 year investment:
yrs
(semi-annually)




------------------------
For 3 year investment:

(quarterly)





------------------------------
If I read the problem right, , the earnings
after 5 years, will become , the principle
invested for 3 years
given:


--------------------
substituting:



and





The original principle invested is $12,264.76
Hope I got it right





Word_Problems_With_Coins/241355: After spending 10% of my weekly income and gave 25% of the remaining and left with RS540 find my weekly income.
1 solutions

Answer 176750 by josmiceli(3007) About Me  on 2009-11-21 11:22:02 (Show Source):
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Let = weekly income

Remaining is
25% of is
given:
is subtracted from weekly income






Weekly income is RS800


Distributive-associative-commutative-properties/239251: Please help me solve this problem
(9sprt6-7sqrt5)(sqrt6-2sqrt5)
Thanks
Cathy
1 solutions

Answer 175694 by josmiceli(3007) About Me  on 2009-11-15 21:37:33 (Show Source):
You can put this solution on YOUR website!





answer
I can check this answer on my calculator



and


I think I made a rounding-off error, but
answer must be OK


Linear-equations/239254: How do I determine whether the following lines are parallel? 3x=y and 2y-6x=5
1 solutions

Answer 175688 by josmiceli(3007) About Me  on 2009-11-15 20:58:07 (Show Source):
You can put this solution on YOUR website!
Get both equations in the form
and if the 's are the same, they are parallel
(they are)


Word_Problems_With_Coins/239245: There are 15 coins consisting of nickels, dimes and quarters. Their total is $1.10. The is one less nickels than four times the dimes. How many of each coin are there? Equation needed.
1 solutions

Answer 175687 by josmiceli(3007) About Me  on 2009-11-15 20:56:13 (Show Source):
You can put this solution on YOUR website!
Let = number of nickels
Let = number of dimes
Let = number of quarters
given:
(1) (in cents)
(2)
There are 3 unknowns, and only 2 equations,
so it will take some extra work to solve
Substitute (2) into (1)


cents
Now just use logic
There can't be 5 quarters, since that's more than
There can't be 4 quarters, since



(can't have 1/2 dime)
I'll try 3 quarters



(can't have 4/3 dimes)
I'll try 2 quarters



(can't have 13/6 dimes)
And 1 quarter



and, since
(2)


There is 1 quarter, 3 dimes, and 11 nickels
check:
(1)



OK


Polynomials-and-rational-expressions/239239: Can someone please help me out? I am lost on this one. I am usually really good with factoring nomials but I have no clue as to how to deal with this one.
factor: x^(2n+1)-2x^(n+1)+x
1 solutions

Answer 175684 by josmiceli(3007) About Me  on 2009-11-15 20:37:46 (Show Source):
You can put this solution on YOUR website!


answer
I just factored it in my head, but completing
the square works, too





Equations/239209: Please help me. I'm having trouble with this problem.
At a given time of day, the ratio of the height of an oject to the length of its shadow is the same for all oject. If a 5ft post casta a shadow of 1.2ft, find the length of the shadow for a 17ft post.
1 solutions

Answer 175681 by josmiceli(3007) About Me  on 2009-11-15 19:52:41 (Show Source):
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Multiply both sides by



The length of the shadow is 4.08 ft


Inequalities/239216: the sum of two consecutive odd integers is 244. what is the smallest integer?
1 solutions

Answer 175676 by josmiceli(3007) About Me  on 2009-11-15 19:42:52 (Show Source):
You can put this solution on YOUR website!
Call the consecutive odd integers and
given:

---------------



The smallest integer is 121
check:

OK


Evaluation_Word_Problems/239218: What is 2,745 rounded to the nearest foot ?
1 solutions

Answer 175675 by josmiceli(3007) About Me  on 2009-11-15 19:36:31 (Show Source):
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what are the units of 2745 ?


Human-and-algebraic-language/238858: The combined age of the Weismillers' two automobiles is 12 years.
Three years ago, Mrs. Weismiller's automobile was double the age of Mr. Weismiller's automobile.How old are Mr. and Mrs. Weismiller's automobiles now?
1 solutions

Answer 175502 by josmiceli(3007) About Me  on 2009-11-14 20:19:12 (Show Source):
You can put this solution on YOUR website!
Age of her car now =
Age of his car now =
Age of her car 3 years ago =
Age of his car 3 years ago =
given:
(1)
(2)
---------------
from (12),

from (2),
(2)


and



Her car is 7 years old and his car is 5 years old


percentage/238861: The sales price of a car is $12,590, which is 20% off the original price. What is the original price?
1 solutions

Answer 175500 by josmiceli(3007) About Me  on 2009-11-14 20:06:23 (Show Source):
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Let = the original price
given:




The original price was $15,737.50


Average/238860: You drove 56 miles one way on a service call. On the return trip your average speed was 8 miles per hour faster and took 10 fewer minutes. What was the average speed on the return trip?
1 solutions

Answer 175497 by josmiceli(3007) About Me  on 2009-11-14 19:59:24 (Show Source):
You can put this solution on YOUR website!
I write 2 equations, 1 for each trip


given:
mi
mi
mi/hr
(10 min is 1/6 hr)
------------------
given:

(1)
and


------------------
(2)
Substitute (1) in (2)

Subtract from both sides

Multiply both sides by

and, from (1)


Multiply both sides by


Use quadratic equation









(the negative answer is impossible)



The speed on the return trip is 56 mi/hr
check answer:
(1)

-----------------------

hr (1 hr 10 min)
and





hr
OK








Polynomials-and-rational-expressions/238659: Find one of the factors when 27a^3-64 is factored completely.
1 solutions

Answer 175357 by josmiceli(3007) About Me  on 2009-11-13 20:09:23 (Show Source):
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The factors are:
and


Functions/238636: Can you explain why y=x^2 is the graph of a function of x, while x=y^2 is not the graph of a function of x?
1 solutions

Answer 175355 by josmiceli(3007) About Me  on 2009-11-13 20:02:06 (Show Source):
You can put this solution on YOUR website!
In order to be a function, each must match with a single
. In the 1st case, , and there can only be
one for each .
In the 2nd case, , and
Each matches with 2 values of
Here's a graph of each. The curve on the right is not a function


Age_Word_Problems/238610: Tim is one-third the age of Jenny. Ellen is one-half the age of Jenny. The sum of their ages is 44, How old is Tim?
1 solutions

Answer 175309 by josmiceli(3007) About Me  on 2009-11-13 16:36:11 (Show Source):
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Let = Tim's age
Let = Jenny's age
Let = Ellen's age
given:



By substitution,

Multiply both sides by



and, since



Tim is 8 years old
check:



and



OK


Travel_Word_Problems/238505: A car and bus set out at the same time. The average speed of the car is 30mph slower than twice the spped of the bus. In two hours, the car is 20 miles ahead of the bus. What is the rate of the car?
1 solutions

Answer 175248 by josmiceli(3007) About Me  on 2009-11-13 10:31:46 (Show Source):
You can put this solution on YOUR website!
I can write 2 equations, 1 for each vehicle

and

---------------
given:
mi/hr
hrs
hrs
mi
---------------
Now I plug in the substitutions



(1)
and

(2)
Substitute (2) in (1)
(1)

mi/hr
and, since


mi/hr
The rate of the car is 50 mi/hr
check:




mi
and



In 2 hours, the car is 20 mi ahead of the bus
OK


Points-lines-and-rays/238342: my question is, y=-3x-4 and line J is perpindicular to the equation, but also passes through point (1,1) what is the answer?
1 solutions

Answer 175147 by josmiceli(3007) About Me  on 2009-11-12 21:07:53 (Show Source):
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If a line has slope = , then
any line perpendicular to it will have
slope =


Perpendicular line J,

So far I know line J has the form
. I know it goes through (1,1),
so I can just plug these values for and
back into the equation for J



The equation for J is
I'll plot the 2 lines to check my work



Triangles/238349: find the range of possible values for the third side of a triangle with sides 2 cm and 5cm
1 solutions

Answer 175140 by josmiceli(3007) About Me  on 2009-11-12 20:45:45 (Show Source):
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Imagine that the sides are connected at one end and laying
right on top of eachother. Then imagine that one of the sides
is rotated a tiny fraction of a degree. The sides are now
, , and plus a tiny length.
Arranged this way, the 3rd side can't be smaller than cm
---------------------------------------------------------------
Now leave the given sides connected at one end, but rotate them
so they are 180 degrees opposite eachother. They now add up to
. Now rotate one of the sides a tiny fraction
of a degree. The sides are now {, , and
minus a tiny length.
Arranged this way, the 3rd side can't be greater than cm
----------------------------------------------------------------
The 3rd side has to be in this range, 3 cm to 7 cm


Percentage-and-ratio-word-problems/238344: Lucy bought a knife set for $500.00 after getting a 10% discount. How much money did Lucy save?
1 solutions

Answer 175138 by josmiceli(3007) About Me  on 2009-11-12 20:33:54 (Show Source):
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Let = the original price of the knife
given:
The discount =
The discounted price =
dollars




Lucy saved $55.56


expressions/237960: I am asked to evaluate the expression: (125/216)^2/3
I am unsure on how to work this out. Can you please help me as I have other problems like this. Thank you so much for your time.
Very respectfully,
Misty
1 solutions

Answer 174912 by josmiceli(3007) About Me  on 2009-11-11 22:19:58 (Show Source):
You can put this solution on YOUR website!

What you have to do is try to express and in
terms of cubes. You can use a calculator or just play with numbersd
until you hit on the answer. Rewrite the equation like this:


Rewrite again

Rewrite again


answer
check answer:

Take the square root of both sides

Cube both sides

OK


Equations/237925: On an algebra test, I had seven times as many correct answers
as incorrect ones. There were 120 items on the
test, how many did I get right?
1 solutions

Answer 174907 by josmiceli(3007) About Me  on 2009-11-11 21:55:17 (Show Source):
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Let = number of incorrect answers
Then = number of correct answers
given:





I got 105 correct


percentage/237550: 135 is what percentage of 1125
1 solutions

Answer 174679 by josmiceli(3007) About Me  on 2009-11-10 23:38:01 (Show Source):
You can put this solution on YOUR website!
Another way to ask the question is:
"What number divided by and
multiplied times will give me
?

Multiply both sides by



is 12% of
check:


OK


Equations/237439: Okay, my question is as follows:
A team is to design a cover a box to hold a jigsaw puzzle. The design will use 525 square cm. The cardboard is precut to 29 cm x 33 cm. The depth of the box (x) can vary to fit the needs of your cover design. How deep should the box be in order to allow the area of 525 cm for your design? I'm puzzled at how to set up this problem...please help me! Thanks!
1 solutions

Answer 174624 by josmiceli(3007) About Me  on 2009-11-10 19:44:49 (Show Source):
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With these box problems, what they do,
usually, is cut small squares out of the corners
and then fold up the 4 equal height sides to
make the box.
So, I'll say that each of these 4 equal squares will have
dimensions cm2
To get the area of the bottom after the sides are
folded up, I subtract from each side.





Use the quadratic formula











and


(can't be answer, too big)
The box has to be 4 cm deep
check answer:





OK


Miscellaneous_Word_Problems/237454: A total of 450 theater tickets were sold. Student tickets sold for $3 and adult tickets sold for $5. If total receipts were $2000, how many of each kind were sold?
1 solutions

Answer 174618 by josmiceli(3007) About Me  on 2009-11-10 19:14:28 (Show Source):
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Let = number of student tickets sold
Let = number of adult tickets sold
given:
(1)
(2)
Multiply both sides of (1) by and
subtract (1) from (2)
(2)
(1)


and, since
(1)
(1)


125 student tickets and 325 adult tickets were sold
check:
(2)
(2)


OK


Unit_Conversion_Word_Problems/237388: Okay so I have this problem that I believe I know how to do, but the only problem is that I don't know how I would convert miles to a year. That was where I was really stuck. Here's the problem:
"Sommer wants to buy a new car. She currently drives a car that gets 30 miles per gallon. She is contemplating buying a car that get's 40 miles per gallon. Sommer drives 15,000 miles per year. Assume that gas costs $1.65 per gallon the entire year. How much will Sommer save on gas in 1 year if she buys the new car?"
I know the question is to find the money amount for how much gas is saved, but then that's also another problem I have is how to find that. If anyone knows how to go about solving this problem or setting it up, please let me know! Thank
you so much!
1 solutions

Answer 174586 by josmiceli(3007) About Me  on 2009-11-10 17:04:43 (Show Source):
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Just looking at the units:
(miles/year) / (miles/gallon) = (miles/year) x (gallons/mile) = gallons/year
given:
She drives miles/year
Her present car gets miles/gallon
gallons/year
The car she wants gets miles/gallon
gallons/year
and
Gas is $/gallon for the year
For old car:
gallons/year x dollars/gallon = dollars/year
For new car:
gallons/year x dollars/gallon = dollars/year

In the 1st year, she'll save $206.25



Mixture_Word_Problems/237399: An advertisement for grape drink claims that the drink contains 10% grape juice. How much pure grape juice would have to be added to 5 quarts of the drink to obtain a mixture containing 40% grape juice?
1 solutions

Answer 174580 by josmiceli(3007) About Me  on 2009-11-10 16:46:00 (Show Source):
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In words:
(quarts of pure grape juice at end)/(total quarts of drink at end) = 40%
given:
Let = quarts of pure grape juice to be added
In quarts of drink, I have
quarts pure grape juice
-----------------------------------------






2.5 quarts of pure grape drink must be added
check:





OK


Numbers_Word_Problems/236019: Mark Martin can row upstream at 5mph and downstream at 11mph. If Mark starts rowing upstream until he gets tired and then rows downstream to his starting point, hhow far did Mark row if the entire trip took 4 hours?
1 solutions

Answer 173776 by josmiceli(3007) About Me  on 2009-11-06 19:39:58 (Show Source):
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Write a separate equation for each
part of the trip
upstream:

(1) mi
downstream:

(2) mi
also:
(I'll call them both )
hrs
hrs
--------------------------
(1)
(2)
(2)
Subtract (1) from (2)



hrs
and, since



-----------------------
(1)

mi
and


mi
Both distances are the same, as they should be
Mark rowed mi



Mixture_Word_Problems/235976: A chemist wants to create 60 grams of an nickel alloy that is 65% pure. She has one mixture of an nickel alloy that is 45% pure and another mixture that is 75% pure. How much of each mixture must she use?

1 solutions

Answer 173771 by josmiceli(3007) About Me  on 2009-11-06 19:22:15 (Show Source):
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Let = grams of 45% mixture to be used
Let = grams of 75% mixture to be used
given:
(1) grams
(2) = pure nickel in final mixture
------------------------------
In words:
( grams of pure nickel in final mixture )/(total grams) = 65%


(3)
Multiply both sides of (1) by and subtract
(1) from (3)
(3)
(1)


And, since



20 grams of the 45% mixture and 40 grams of the 75% mixture are needed
check:





OK


Systems-of-equations/235958: A mixture of 10% acid and 90% water is added to 5 liters of pure acid. The final mixture is 40% water. How many liters of water are in the final mixture?
1 solutions

Answer 173734 by josmiceli(3007) About Me  on 2009-11-06 15:27:49 (Show Source):