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all answered: 299 problems
Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149 , 150..179 , 180..209 , 210..239 , 240..269 , 270..299, >>NextLinear-equations/751777: I have a problem on a homework assignment. The problem says: A farmhouse shelters 10 animals. Some are pigs and some are ducks. Together, there are 36 legs. How many of each are there?
1 solutions
Answer 457394 by JoeTaxpayer(116) on 2013-05-22 22:12:19 (Show Source):
You can put this solution on YOUR website!4P+2D=36 i.e. 4 times the number of pigs is the number of pig-feet, 2D = duck-feet
P+D=10 ten animals total.
Multiply second equation by 4:
4P+4D=40
4P+2D=36 (and subtract first equation.
2D=4
2 ducks, 8 pigs. 10 animals.
4 duck feet + 32 pig-feet, total 36 feet.
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Surface-area/751782: The height of the cylinder is three times the diameter of the base. The surface area of the cylinder is 126. What is the radius of the base 1 solutions
Answer 457393 by josgarithmetic(1517) on 2013-05-22 22:11:34 (Show Source):
You can put this solution on YOUR website!Say the diameter is d and the radius is  .
Let h= height of the cylinder.
circumference is the LENGTH of the rounded side. This circumference is  , or
circumference is
The surface area then is 
and you were given in the description:
 .
Solving for d is uncomplicated.
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Quadratic_Equations/751745: Solve: 16x^2-72x=-85
Not sure if I'm suppose to factor or use the quadratic equation? Help would be appreciated! :) 1 solutions
Answer 457390 by josmiceli(9678) on 2013-05-22 22:04:58 (Show Source):
You can put this solution on YOUR website!
I don't know which method they want you to use, but
I can try completing the square
---------------------
First, divide both sides by

--------------------------
Take 1/2 of the coefficient of  ,
square it, and add it to both sides

Take the square root of both sides

and, also

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Here's the plot:

Since it doesn't contact the x-axis, there are no real roots
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Rate-of-work-word-problems/751778: George and Stanley are building a stone fence. They can complete the fence together in 8 hours, and George can complete it is 24 hours working alone. If they work together for 6 hours, then Stanley goes to the pub for a pint, how much longer must George work to finish the fence? 1 solutions
Answer 457389 by stanbon(57346) on 2013-05-22 22:03:22 (Show Source):
You can put this solution on YOUR website!George and Stanley are building a stone fence. They can complete the fence together in 8 hours, and George can complete it is 24 hours working alone.
----
George & Stan together rate::: 1/8 job/hr
George rate::::: 1/24 job/hr
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If they work together for 6 hours, then Stanley goes to the pub for a pint, how much longer must George work to finish the fence?
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6(1/8) + x/24 = 1 job
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3/4 + x/24 = 1
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18 + x = 24
x = 6 hrs. (Time George needs to finish)
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Cheers,
Stan H.
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Expressions-with-variables/751423: A man flies a small airplane from Fargo to Bismarck, North Dakota --- a distance of 180 miles. Because he is flying into a head wind, the trip takes him 2 hours. On the way back, the wind is still blowing at the same speed, so the return trip takes only 1 hour 12 minutes. What is his speed in still air, and how fast is the wind blowing?
His speed equals--
The wind speed equals-- 1 solutions
Answer 457387 by ankor@dixie-net.com(15652) on 2013-05-22 21:56:36 (Show Source):
You can put this solution on YOUR website!A man flies a small airplane from Fargo to Bismarck, North Dakota --- a
distance of 180 miles.
Because he is flying into a head wind, the trip takes him 2 hours.
On the way back, the wind is still blowing at the same speed, so the
return trip takes only 1 hour 12 minutes.
What is his speed in still air, and how fast is the wind blowing?
:
Change 1 hr 12 min: 1 + 12/60 = 1.2 hrs
:
Let s = his speed in still air
Let w = speed of the wind
then
(s-w) = effective speed against the wind
and
(s+w) = effective speed with the wind
:
Write a distance equation for each way; dist = time * speed
2(s - w) = 180
1.2(s+w) = 180
Simplify both equations, divide the 1st eq by 2, the 2nd eq by 1.2; results:
s - w = 90
s + w = 150
-------------addition eliminates w, find s
2s = 240
s = 240/2
s = 120 mph is the speed in still air
Find w
s + w = 150
120 + w = 150
w = 150 - 120
w = 30 mph is the speed of the wind
:
Check in 1st original equation
2(120-30) = 180
2(90) = 180
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Linear-equations/751776: Determine whether these equations are parallel, perpendicular, or neither.
8x=5y+3
-24x=15y+3
Solve: 1/4x-1; (20, ) ( ,-3) I need to find the missing numbers.
Thank you. 1 solutions
Answer 457386 by stanbon(57346) on 2013-05-22 21:51:06 (Show Source):
You can put this solution on YOUR website!Determine whether these equations are parallel, perpendicular, or neither.
8x=5y+3
-24x=15y+3
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y = (8/5)x - (3/5)
y = (-8/5)x - (1/5)
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The slopes are (8/5) and (-8/5)
The lines are not parallel or perpendicular.
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Cheers,
Stan H.
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percentage/751772: Tracey paid $190 for an item that was originally priced at $290. What percent of the original price did Tracey pay?
2 solutions
Answer 457385 by stanbon(57346) on 2013-05-22 21:44:00 (Show Source):
You can put this solution on YOUR website!Tracey paid $190 for an item that was originally priced at $290. What percent of the original price did Tracey pay?
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x/100 = 190/290
x = 100(190/290)
x = 65.52%
------------------------
Cheers,
Stan H.
Answer 457384 by josmiceli(9678) on 2013-05-22 21:38:58 (Show Source):
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Coordinate-system/751689: Determine whether the lines x-5y=15 and -5x-y+2=0 are parallel, perpendicular, or neither.
I really need help with this one. Kim 2 solutions
Answer 457382 by MathTherapy(1424) on 2013-05-22 21:14:18 (Show Source):
You can put this solution on YOUR website!
Determine whether the lines x-5y=15 and -5x-y+2=0 are parallel, perpendicular, or neither.
I really need help with this one. Kim
x - 5y = 15 has a slope of  , while - 5x - y + 2 = 0 has a slope of  .
Since these two slopes are negative reciprocals of each other:  and  , then the slopes are perpendicular to each other.
Answer 457367 by tommyt3rd(545) on 2013-05-22 19:08:10 (Show Source):
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Permutations/751761: A die is rolled four times. Find P(four of the same number) 1 solutions
Answer 457381 by JoeTaxpayer(116) on 2013-05-22 21:13:27 (Show Source):
You can put this solution on YOUR website!it's 1 in 6^3 or 1 in 216.
Why not 1 in 6^4?
It would be that if you asked the chances of 4 rolls of a particular number, but here it's just the same, so the first roll is 'free.' only the next three rolls must match.
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Sequences-and-series/751737: A side of an equilateral triangle is 10 cm. the midpoints of its sides are joined to form an inscribed equilateral triangle, and this process is continued. Find the sum of the perimeters of the triangles if the process is continued without end. 1 solutions
Answer 457378 by reviewermath(522) on 2013-05-22 20:17:42 (Show Source):
You can put this solution on YOUR website!Perimeter of first triangle: 30 cm
second triangle: 15 cm
third triangle: 7.5 cm
...
nth triangle: 
...
The sum of an infinite geometric series with first term  and common ratio r is  provided |r| < 1.
 =  =  cm.
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Probability-and-statistics/751665: ``During a drug trial for a new anitbotic, 45% of the people woh were given the drug experienced dizziness.
Assume a sample size of 15 patients..
Find the probability that less than 6 patients experienced dizziness.
Find the probability that at least 7 patients experienced dizziness.
Find the probability that at most 4 patients did NOT experience dizziness. 1 solutions
Answer 457377 by reviewermath(522) on 2013-05-22 20:00:33 (Show Source):
You can put this solution on YOUR website!
Find the probability that less than 6 patients experienced dizziness.
X ~ Binomial(15, 0.45)
P(X < 6) =  =
Find the probability that at least 7 patients experienced dizziness.
X ~ Binomial(15, 0.45)
P(X ≥ 7) =  =
Find the probability that at most 4 patients did NOT experience dizziness.
X ~ Binomial(15, 0.55)
P(X ≤ 4) =  =
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Polynomials-and-rational-expressions/751675: y^3+125.. please factor completely... if its prime that is also one of the options on my question. Thank you 1 solutions
Answer 457375 by reviewermath(522) on 2013-05-22 19:42:49 (Show Source):
You can put this solution on YOUR website!Factoring the Sum of Two Cubes:
Step 1: Get the binomial factor
Cube root of the first term: y
Cube root of the second term: 5
The binomial factor is y + 5
Step 2: Get the trinomial factor
Square of the first term of the binomial factor: 
Negative Product of the first and second term of the binomial factors = -5y
Square of the second term of the binomial factor: 25
The trinomial factor is 
Step 3: The factored form of  is  .
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Quadratic-relations-and-conic-sections/751709: Write an equation for the circle with the endpoints of the diameter at (-6,4) and (4,8) 1 solutions
Answer 457372 by reviewermath(522) on 2013-05-22 19:33:57 (Show Source):
You can put this solution on YOUR website!First, get the length of the diameter by computing the
distance between the points (-6, 4) and (4, 8).
Using the distance formula:
d =
= 
= 
The length of the radius is half the length of the diameter.
r =  =  .
Next, we get the coordinates of the center of the circle by
computing the midpoint of the diameter with endpoints (-6,4) and (4,8).
Using the midpoint formula:
center = (  ,  )
= (-1, 6)
The equation of the circle with center (h,k) and radius r is
 , the center is (h,k) = (-1,6) and radius, r = 
Equation:
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Trigonometry-basics/751257: Can you help me solve the equations for x, if 0is less than equal to x is less than equal to 2pi.
a) 8cos^2x=4 1 solutions
Answer 457370 by lwsshak3(6505) on 2013-05-22 19:30:25 (Show Source):
You can put this solution on YOUR website! solve the equations for x, if 0is less than equal to x is less than equal to 2pi.
a) 8cos^2x=4
cos^2(x)=4/8=1/2
cos(x)=1/√2=√2/2
x=π/4, 3π/4 (in Q1 and Q2 where sin>0)
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Trigonometry-basics/750962: how to find the value of sin 1380 cos 225 and tan 420 1 solutions
Answer 457366 by lwsshak3(6505) on 2013-05-22 19:05:06 (Show Source):
You can put this solution on YOUR website!how to find the value of sin 1380 cos 225 and tan 420
***
1380-3*360=1380-1080=300
sin(1380)=sin(300)=sin(60)=-√3/2 (in Q4 where sin<0)
..
cos(225)=cos(45)=-√2/2 (in Q3 where cos<0)
..
420-360=60
tan(420)=tan(60)=√3 (in Q1 where tan>0)
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Quadratic_Equations/751687: You are building a rectangular deck. The area of the deck should be 250 ft squared. You want the length of the deck to be 5 ft longer than twice its width. What should the dimensions of the deck be?
Any help is appreciated 1 solutions
Answer 457362 by rothauserc(208) on 2013-05-22 18:36:29 (Show Source):
You can put this solution on YOUR website!You are building a rectangular deck. The area of the deck should be 250 ft squared. You want the length of the deck to be 5 ft longer than twice its width.
let w be the width and 2w+5 is the length, then
w(2w+5) = 250
2w^2+5w-250=0
(2w+25) * (w-10) = 0 and
w=10 and l = 25
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