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Find the circumference and area of the circle whose equation is x^2 + y^2 =36. Round to the nearest tenth. 1 solutions
Answer 214393 by josmiceli(9664) on 2010-04-28 13:30:13 (Show Source):
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Quadratic_Equations/297403: I am having trouble with writing in 50 words why the line x=4 is a vertical line. I think that x=4 is a vrtical line because it is perpindicular to the y axis.Can you help me please? I would very much appreciate it. 1 solutions
Answer 214204 by josmiceli(9664) on 2010-04-27 19:16:19 (Show Source):
You can put this solution on YOUR website!The thing to think about is this: No matter what this line
looks like you know that every point imaginable on the line
must satisfy it's equation which is  whatever
 ends up being. The line is perpendicular to the  axis
at  .
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Age_Word_Problems/297444: Hot chocolate sells for $.75 and coffee sells for $.50 at a football game. If they sold $200 worth of hot drinks and used 295 cups, how many of each drink did they sell? 1 solutions
Answer 214201 by josmiceli(9664) on 2010-04-27 19:10:27 (Show Source):
You can put this solution on YOUR website!Let  = number of hot chocolates sold
Let  = number of coffees sold
given:
(1) 
(2) 
Multiply both sides of (1) by 
and subtract from (2)

and, since

They sold 210 hot chocolates and 85 coffees
check:
(2) 
(2)

OK
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Proportions/297433: a student answered 87.5% of the exam correctly. if she answered 42 problems correctly, how many questions were therer on the exam? 1 solutions
Answer 214189 by josmiceli(9664) on 2010-04-27 18:50:36 (Show Source):
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Polynomials-and-rational-expressions/297418: A number minus twice its reciprocal is the same as the reciprocal of four times the number. find the number.
I have the equation as x-2 1/x = 1/4x
then i multiplied 2 by 1/x and got 2/x
Then i changed the x/1-2/x into the same base so we can subtract and got (x^2-2)/x + 1/4x
From there i am lost. 1 solutions
Answer 214184 by josmiceli(9664) on 2010-04-27 18:39:47 (Show Source):
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Linear-equations/297417: How to you solve :
2x + 4y=8 1 solutions
Answer 214182 by josmiceli(9664) on 2010-04-27 18:29:38 (Show Source):
You can put this solution on YOUR website!You can't solve this. Solving means to find the
numerical values of the unknowns, x and y
In order to solve, the number of unknowns must
equal the number of equations. You have 2 unknowns
and only 1 equation.
You can make an x-y plot of the equation. It's a
straight line and here it is:
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Systems-of-equations/297277: Sammy sold 700 tickets totaling $13330. If the tickets were $25 adi;ts amd $15 students, how many of each ticket did Sammy sell?
1 solutions
Answer 214087 by josmiceli(9664) on 2010-04-27 14:05:40 (Show Source):
You can put this solution on YOUR website!Let  = number of adult tickets sold
Let  = number of student tickets sold
given:
(1) 
(2) 
-----------------------
Multiply both sides of (1) by  and
subtract from (2)

and, since

Sammy sold 283 adult and 417 student tickets
check:

OK
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Finance/297266: What are the algebraic formulas for this (in a collection of nickels, dimes, and quarters, there are twice as many dimes as nickels and 3 fewer quarters than dimes. if the total value is $4.50 how many of each coin are there) 1 solutions
Answer 214077 by josmiceli(9664) on 2010-04-27 13:43:33 (Show Source):
You can put this solution on YOUR website!Let  = number of nickels
Let  = number of dimes
Let  = number of quarters
given:
 (in cents)
--------------------------
This is 3 equations and 3 unknowns, so it's solvable
By substitutions:

And, substituting again:

and, since

and

There are 14 dimes, 11 quarters, and 7 nickels
check:

OK
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Travel_Word_Problems/297242: If i ride my bike 8 miles and then walk 4 miles it takes me 3hrs. If i walk 1/4 the rate that i ride, how fast did i ride my bike? 1 solutions
Answer 214073 by josmiceli(9664) on 2010-04-27 13:27:35 (Show Source):
You can put this solution on YOUR website!Let  = your speed riding your bike
Then, your speed walking is 
In words:
(time spent walking and biking) = (distance biking/biking speed) + (distance walking/walking speed)

Multiply both sides by

The speed biking is 8 mi/hr
check:

OK
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Travel_Word_Problems/297107: A dog is walking along a train track on e day, and traceled along that track onto a train bridge. When the dog was 1/4 of the way across the bridge, he heard a train whistle from an oncoming train that was coming in the same direction the dog had already come. The dog bounded away form the train, and made it to the end of the bridge at exactly the same time as the train. What the dog didn't know, but what was also true, was that the dog could have bounded toward th train and made it to the "start" of the bridge at exactly the same time as the traing. The train was traceling at a speed of 30 mph. How fast was the dog traveling? 1 solutions
Answer 213973 by josmiceli(9664) on 2010-04-27 03:36:04 (Show Source):
You can put this solution on YOUR website!Let  = the dog's speed running
Let  = the time for the train to just reach the bridge
Let  = the length of the bridge in miles
-------------------------
In words:
(dog's speed) x (time for train to reach bridge + time for train to cross bridge) = (3/4)x(the length of the bridge)
As an equation:
(1) 
---------------------------
In words:
(dog's speed) x (time for train to reach bridge) = (1/4)*(length of bridge)
As an equation:
(2) 
---------------------------
In words:
(train's speed plus dog's speed) x (time for train to reach bridge) = (distance train travels to reach bridge plus distance dog runs)
As an equation:
(3) 
----------------------------
This is 3 equations and 3 unknowns, so it's solvable
(1) 
(1) 
(1) 
and
(2) 
and
(3) 
(3) 
(3) 
I can substitute (2) in (1)
(1) 
(1) 
(1) 
(1) 
The dog was running 15 mi/hr
check answer:
(2) 
(2) 
(2) 
Substitute in (3)
(3) 
(3) 
(3) 
OK
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Finance/297117: how many liters of 40% solution has to be added to 10 leiters of 80% to make 60%?
I need linier equations with 2 viariables to solve 1 solutions
Answer 213970 by josmiceli(9664) on 2010-04-27 02:25:06 (Show Source):
You can put this solution on YOUR website!Let  = liters of 40% solution needed
Let  = liters of 60% solution you end up with
given:
(1) 
(2) 
-------------------------------------
from (2),
(2)

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

and
 answers
--------------------------
check answers:

and, since

(2) 
(2)

OK
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Travel_Word_Problems/296684: A jet fighter cruises at 1.5 times the speed of sound. The speed of sound is 1.24x10^3 km/hr. How many hours does it take for the jet to fly the 5.8x10^3 from new york to paris. Demonstrate the use of scientific method. 1 solutions
Answer 213755 by josmiceli(9664) on 2010-04-26 11:59:21 (Show Source):
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Travel_Word_Problems/296377: Two trains are coming at each other at sixty miles an hour, one from Chicago, one from Los Angeles. Given an East South East wind of 15 mph in Eastern Colorado, which train uses more fuel to reach its destination? 1 solutions
Answer 213580 by josmiceli(9664) on 2010-04-25 17:59:31 (Show Source):
You can put this solution on YOUR website!I'm guessing a little, but I believe the wind is OUT OF
the ESE direction, so the train from Chicago will have a tailwind
(helping), and the train from LA will have a headwind (slowing it)
So, the train from Chicago should use less fuel.
(assuming they both have the same, or nearly the same, fuel efficiency)
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Functions/296402: The gas mileage, m, of a specific car is a linear function of the speed, s, at which the car is driven,for 60 less that or equal to s less than or equal to 30. if the car is driven at a rate of 30MPH, the cars gas mileage is 35MPG. If the car is driven at 60MPH the cars gas mileage is 20MPG. I need to use this data (s,m) to write an equation for the gas mileage m. I have know idea how to do this! 1 solutions
Answer 213576 by josmiceli(9664) on 2010-04-25 17:47:28 (Show Source):
You can put this solution on YOUR website!You need to plot this the same way you plot 
Plot gas milage, (m) on the vertical axis and
speed, (s) on the horizontal axis. This is  .
You are told that it's a straight line between 
and  .
Essentially what you are given is two points, (s,m) on this line
(30,35) and
(60,20)
Now you need the point-slope formula which looks like:

Multiply both sides by

This is gas milage as a function of speed
Here's a plot:

Remember that the plot is only good between  and
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Geometry_Word_Problems/293198: A circle of radius 2 rolls completely around the inside perimeter of a square of side 10. what distance is covered by the centre of the circle ?
a 16 b 24 c 32 d 40 1 solutions
Answer 211675 by josmiceli(9664) on 2010-04-17 12:32:51 (Show Source):
You can put this solution on YOUR website!It will trace out a square who's sides
are 1 radius away from the outside square
The outside square's sides are  units
apart. The inside square's sides are 
smaller, so

The perimeter of a square with sides = 6 is
 units
The answer is (b)
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logarithm/293221: CAN YOU PLS TELL ME HOW TO SOLVE LOG 0.3 to the base 9..??
The answer should be 1/2.
1 solutions
Answer 211674 by josmiceli(9664) on 2010-04-17 12:23:08 (Show Source):
You can put this solution on YOUR website!The main thing to remember is: LOGS ARE EXPONENTS
The other main thing is:
You have to know how to read this:

First of all, it's telling you that  is an exponent,
since it says "y = log(something)"
Then it tells you that when you raise the base  to
the exponent  , the result is 
Putting all that together:

You can also express  as

The rule for this is to multiply the exponents

You can solve this on a calculator, or
take the log to the base  of both sides

-----------------
Actually,

and, as I showed,
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Average/293200: A week ago, Sandy’s seasonal Little League batting average was 360. After five more at bats this week, Sandy’s batting average is up to 400. What is the smallest number of hits that Sandy could have had this season? 1 solutions
Answer 211659 by josmiceli(9664) on 2010-04-17 10:41:33 (Show Source):
You can put this solution on YOUR website!The batting average is (hits)/(number of times at bat) x 1000
Let  = times at bat last week
Let  = number of hits last week
Let  = number of hits this week
(1) 
and after this week:
(2) 
------------------------------
This is 2 equations and 3 unknowns, so it isn't
directly solvable, but it can be analyzed
From (1):
(1)

and from (2)

I know that 
Suppose
 ends up being (-), so that doesn't work
Suppose  . Then  , and that can't be
Suppose

From (1)

and from (2):
(2) 
(2) 
The smallest number of hits Sandy could have got this
season is  , or 12 hits

OK
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Travel_Word_Problems/293156: a car driving in fog passed a man walking at 3km\hr in a same direction. he could see the car for 4 minute and up to a distance 100 meter
.what was speed of the car? 1 solutions
Answer 211652 by josmiceli(9664) on 2010-04-17 10:10:52 (Show Source):
You can put this solution on YOUR website!I think that their relative speed is  km/hr
where  is the speed of the car.
The car looks like it's going  km/min
or  km/min x  min/hr =  km/hr

The speed of the car is 4.5 km/hr
Hope I got it right
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Travel_Word_Problems/292740: An airplne flew for 4 hours with a 20 km/hour tail wind. The return flight against the same wind took 5 hours. Find the speed of the plane in still air.
I am having trouble finding the distance flown to figure out the answer. 1 solutions
Answer 211390 by josmiceli(9664) on 2010-04-15 20:30:36 (Show Source):
You can put this solution on YOUR website!Let  = wind speed
Let  = speed of plane in still air
 = speed of plane flying with the wind
 = speed of plane flying against the wind
--------------------
Flying with the wind:
 km
(1)  km
Flying against the wind:
 km
(2)  km
Since  is the same in (1) and (2), they
are equal to eachother

The plane's speed in still air is 180 km/hr
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Pythagorean-theorem/292741: The base path of a baseball diamond forms a square. If it is 90 ft. from home to first, how far does the catcher have to throw to catch someone stealing second base?
Give your answer as a radical expresion in simplest form and then stimate the lenght to the nearest tenth of a foot. 1 solutions
Answer 211378 by josmiceli(9664) on 2010-04-15 20:10:26 (Show Source):
You can put this solution on YOUR website!It is telling you that  ft is one
side of the square, and it is asking you
for the distance between opposite corners.
The sides are all equal to  ft
and, for a square, the diagonal and a side
are in the ratio  to  ,
so I can say 
Multiply both sides by
 ft (rounded to nearest 1/10 th)
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