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Proportions/678994: I need help with finding an equation for:
A piece of wire is 5 feet long is to be cut into 2 pieces, one piece is X feet long and is bent into the shape of an equilateral triangle. the other piece is bent into a circle. Find an equation for the total area of the triangle and the circle as a function of X.

1 solutions

Answer 421724 by josmiceli(9679) About Me  on 2012-11-11 23:09:35 (Show Source):
You can put this solution on YOUR website!
The whole length of wire is +5+ ft
+x+ ft is used for the equilateral triangle
+5+-+x+ is used for the circle
-----------------
The area of the triangle is A+=++%281%2F2%29%2Ab%2Ah+
The base is +x%2F3+ . The height is +%281%2F2%29%2A%28x%2F3%29%2Asqrt%283%29+
+A+=+%281%2F2%29%2A%28x%2F3%29%2A%28x%2F6%29%2Asqrt%283%29+
+A+=+%28+x%2Asqrt%283%29%29+%2F+36+
----------------------
The area of the circle is +pi%2Ar%5E2+
To find r, find the circumference
+C+=+2%2Api%2Ar+
+5+-+x+=+2%2Api%2Ar+
+r+=+%28+5+-+x+%29+%2F+%282%2Api%29+
and
+A+=+pi%2A%285+-+x%29%5E2+%2F+%28+4%2Api%5E2+%29+
+A+=+%281%2F%284%2Api%29%29%2A%28+25+-+10x+%2B+x%5E2+%29+
Hope I got it



Linear-equations/678690: I am trying to solve this equation for y
(x/3)-(y/8)=1
I have gotten this far and I am stuck
(-y/8)=1-(x/3)
y= -8(1-(x/3)
1 solutions

Answer 421586 by josmiceli(9679) About Me  on 2012-11-11 11:42:16 (Show Source):
You can put this solution on YOUR website!
+%28x%2F3%29+-+%28y%2F8%29=1++
I would start by multiplying both sides by
the LCD, +24+
+8x+-+3y+=+24+
add +3y+ to both sides
+8x+=+24+%2B+3y+
Subtract +24+ from both sides
+3y+=+8x+-+24+
Divide both sides by +3+
+y+=+%288%2F3%29%2Ax+-+8+
--------------------
Also, doing it the other way:
+%28x%2F3%29+-+%28y%2F8%29=1++
+y%2F8+=+x%2F3+-+1+
+y+=+%288%2F3%29%2Ax+-+8+
OK



Linear-equations/678688: How do I find the distance between the following pairs of points (-2,-5) and (-2,3).
Also, how do i find the slope of the line segments joining them.
Help is appreciated, thank you very much.
1 solutions

Answer 421583 by josmiceli(9679) About Me  on 2012-11-11 11:14:56 (Show Source):
You can put this solution on YOUR website!
The distance formula is:
+d+=+sqrt%28+%28+x%5B2%5D+-+x%5B1%5D+%29%5E2+%2B+%28+y%5B2%5D+-+y%5B1%5D+%29%5E2+%29+
given:
P1 ( -2,-5 )
P2 ( -2, 3 )
+d+=+sqrt%28+%28+-2+-%28-2%29+%29%5E2+%2B+%28+3+-%28-5%29+%29%5E2+%29+
+d+=+sqrt%28++%28-2+%2B+2++%29%5E2+%2B+%28+3+%2B+5+%29%5E2+%29+
+d+=+sqrt%28++0%5E2+%2B+8%5E2+%29+
+d+=+sqrt%28+8%5E2+%29+
+d+=+8+
------------
The slope is ( change in y ) / ( change in x )
slope = +%28+3+-+%28-5%29+%29+%2F+%28+-2+-+%28+-2+%29+%29+
slope = +%28+3+%2B+5+%29+%2F+%28+-2+%2B+2+%29+
slope = +8+%2F+0+
When +0+ is in the denominator of a slope, that
means the slope is infinite, and that means it is a vertical line
through ( -2, y ) where y can be anything


percentage/678678: One day Tom buys an electric drill when the shop offers a 20% discount. The next day jake buys and identical drill but the discount is then 25%. If tom paid $4 more than Jake,what was the orginal price of the drill?
1 solutions

Answer 421581 by josmiceli(9679) About Me  on 2012-11-11 10:44:46 (Show Source):
You can put this solution on YOUR website!
Let +x+ = the original price of the drill
given:
+x+-+.2x+=+x+-+.25x+%2B+4+
+.8x+=+.75x+%2B+4+
+.05x+=+4+
+x+=+4%2F.05+
+x+=+80+
The original pice was $80
check:
+x+-+.2x+=+x+-+.25x+%2B+4+
+80+-+.2%2A80+=+80+-+.25%2A80+%2B+4+
+80+-+16+=+80+-+20+%2B+4+
+64+=+64+
OK


Miscellaneous_Word_Problems/678500: If 15 out of 25 families on the block own cats, what is the percentage of families that own cats?

1 solutions

Answer 421462 by josmiceli(9679) About Me  on 2012-11-10 17:03:13 (Show Source):
You can put this solution on YOUR website!
percentage means per one hundred, so
+15%2F25+=+x%2F100+
+3%2F5+=+x%2F100+
Multiply both sides by +100+
+60+=+x+
60% own cats
---------------
But, if you haven't had algebra yet,
+3%2F5+=+.6+
+.6%2A100+=+60+
60% own cats


Surface-area/678359: Please reply, I'm only a 8th grade student..
What is the surface area in centimeters and the same area in millimeters ?
1 solutions

Answer 421314 by josmiceli(9679) About Me  on 2012-11-09 20:58:43 (Show Source):
You can put this solution on YOUR website!
It's kind of a general question, but I'll try.
Suppose you have a rectangle that is
3 meters on one side and 5 meters on the other side
The area of the rectangle is +3%2A5+=+15+ square meters
----------------
To convert the area to square centimeters,
( meters ) x ( 100 centimeters / meter )
+3%2A100+=+300+ centimeters
and
+5%2A100+=+500+ centimeters
To get the area, multiply
+300%2A500+=+150000+ square centimeters
-----------------
To convert the area to square millimeters,
( meters ) x ( 1000 millimeters / meter )
+3%2A1000+=+3000+ millimeters
and
+5%2A1000+=+5000+ millimeters
To get the area, multiply
+3000%2A5000+=+15000000+ square millimeters
-----------------
Hope this helps.




Miscellaneous_Word_Problems/678322: A piece of land containing 30 acres sells for $5,000. At the same rate, what would 22 acres sell for?
1 solutions

Answer 421278 by josmiceli(9679) About Me  on 2012-11-09 16:34:00 (Show Source):
You can put this solution on YOUR website!
Find out what 1 acre sells for
+5000%2F30+=+166.67+
1 acre sells for $166.67
+22%2A166.67+=+3666.67+
22 acres sell for $3,666.67


test/678025: A motorboat can maintain a constant speed of 16mph relative to the water. The boat makes a trip upstream to a certain point in 20 minutes; the trip takes 15 minutes. What is the current's speed?
1 solutions

Answer 421153 by josmiceli(9679) About Me  on 2012-11-08 21:31:53 (Show Source):
You can put this solution on YOUR website!
Let +c+ = the speed of the current
+16+-+c+ = the boat's speed going upstream
+16+%2B+c+ = the boat's speed going downstream
given:
Going upstream:
(1) +d+=+%28+16+-+c+%29%2A%281%2F3%29+
Going downstream:
(2) +d+=+%28+16+%2B+c+%29%2A%281%2F4%29+
------------------------
Substitute (1) into (2)
+%28+16+-+c+%29%2A%281%2F3%29+=+%28+16+%2B+c+%29%2A%281%2F4%29+
Multiply both sides by +12+
+4%2A%28+16+-+c+%29+=+3%2A%28+16+%2B+c+%29+
+64+-+4c+=+48+%2B+3c+
+7c+=+16+
+c+=+16%2F7+
+c+=+2.286+
The current's speed is 2.286 mi/hr


Travel_Word_Problems/678035: On a 370-mile trip, Andy averaged 5 miles per hour faster for the last 160 miles than he did for the first 210 miles. The entire trip took 10 hours. How fast did he travel for the first 210 miles?
I have tried so many different ways to solve and just can't! my teacher didn't go over any of this!
1 solutions

Answer 421151 by josmiceli(9679) About Me  on 2012-11-08 21:19:23 (Show Source):
You can put this solution on YOUR website!
You need 2 equations, 1 for the first 210 miles
and another for the last 160 miles
Let +t+ = his time in hrs for the 1st 210 miles
Let +s+ = his speed for the 1st 210 miles
+10+-+t+ = his time in hrs for the last 160 miles
+s+%2B+5+ = his speed for the last 160 miles
--------------------------------------
Equation for the first 210 miles:
(1) +210+=+s%2At+
Equation for the last 160 miles
(2) +160+=+%28+s+%2B+5+%29%2A%28+10+-+t+%29+
----------------------------
(2) +160+=+10s+%2B+50+-+s%2At+-+5t+
(2) +10s+-+s%2At+-+5t+=+110+
and
(1) +s+=+210%2Ft+
Substitute (1) into (2)
(2) +10%2A%28210%2Ft%29+-+%28210%2Ft%29%2At+-+5t+=+110+
(2) +2100%2Ft+-+210+-+5t+=+110+
Multiply both sides by +t+
(2) +2100+-+210t+-+5t%5E2+=+110t+
(2) +5t%5E2+%2B+320t+=+2100+
(2) +t%5E2+%2B+64t+=+420+
complete the square
(2) +t%5E2+%2B+64t+%2B+%2864%2F2%29%5E2+=+420+%2B+%2864%2F2%29%5E2+
(2) +t%5E2+%2B+64t+%2B+1024+=+420+%2B+1024+
(2) +%28+t+%2B+32+%29%5E2+=+1444+
Take the square root of both sides
(2) +t+%2B+32+=+38+
(2) +t+=+6+
and, since
(1) +210+=+s%2At+
(1) +210+=+s%2A6+
(1) +s+=+210%2F6+
(1) +s+=+35+
His speed for the 1st 210 miles was 35 mi/hr
check:
(2) +160+=+%28+s+%2B+5+%29%2A%28+10+-+t+%29+
(2) +160+=+%28+35+%2B+5+%29%2A%28+10+-+t+%29+
(2) +160+=+40%2A%28+10+-+t+%29+
(2) +10+-+t+=+4+
(2) +t+=+6+
OK





Evaluation_Word_Problems/677885: The problem:
A library receives a large cash donation and uses the funds to double the number of books it owns. Then a book collector gives the library 4028 books. After this, the library has 51,514 books. How many books did the library have before the cash donation and the gift of books?
I've been trying so many different ways to solve this and I can't figure out how you would find out many books they had originally. I needed to define a variable and write an equation for the situation then solve it. I'm very confused can someone please explain this to me?
1 solutions

Answer 421128 by josmiceli(9679) About Me  on 2012-11-08 20:08:16 (Show Source):
You can put this solution on YOUR website!
the library started with an unknown +x+ number of books
The cash donation allowed them to double that number, so
then they had +2x+ books
Then a book collector gave the library 4028 books, so then
they had +2x+%2B+4028+ books
The total after that was +51514+ books, so
+2x+%2B+4028+=+51514+
+2x+=+51514+-+4028+
+2x+=+47486+
+x+=+23743+
The library started with 23,743 books


Miscellaneous_Word_Problems/677866: The Blakes went to an ice cream place where a small cone costs $1.85, a medium cone costs $2.35, a large cone costs $2.75. There are 5 people in the Blake family and each person ordered one cone. If they spent a total of $11.65, how many medium cones did they buy?
1 solutions

Answer 421109 by josmiceli(9679) About Me  on 2012-11-08 17:22:02 (Show Source):
You can put this solution on YOUR website!
they could not have all ordered large cones
since that adds up to +2.75%2A5+=+13.75+
---------
There can't be 4 large cones since that adds
up to +2.75%2A4+=+11+ and that would only
leave 65 cents for the 5th cone
--------
Can there be 3 large cones and 2 mediums?
+2.75%2A3+%2B+2.35%2A2+=+8.25+%2B+4.7+
+8.25+%2B+4.7+=+12.95+ No, that's too much
--------
Can there be 3 large, 1 medium and 1 small?
+2.75%2A3+%2B+1%2A2.35+%2B+1%2A1.85+=+8.25+%2B+2.35+%2B+1.85+
+8.25+%2B+2.35+%2B+1.85+=+12.45+ Still too much
--------
Can there be 3 large and 2 small?
+2.75%2A3+%2B+1.85%2A2+=+8.25+%2B+3.7+
+8.25+%2B+3.7+=+11.95+ Too much
--------
That means there can be at most 2 large cones
Can there be 2 large and 3 mediums?
+2.75%2A2+%2B+2.35%2A3+=+5.5+%2B+7.05+
+5.5+%2B+7.05+=+12.55+ Too much
---------
Can there be 2 large and 3 small?
+5.5+%2B+3%2A1.85+=+5.5+%2B+5.55+
+5.5+%2B+5.55+=+11.05+ Too low
---------
Can there be 2 large, 2 small and 1 medium?
+5.5+%2B+3.7+%2B+2.35+=+11.55+ Too small
---------
Can there be 2 large, 2 medium, and 1 small?
+5.5+%2B+4.7+%2B+1.85+=+12.05+ Too much
----------
It looks like there can only be 1 large
Can there be 1 large and 4 mediums?
+2.75+%2B+4%2A2.35+=+2.75+%2B+9.4+
+2.75+%2B+9.4+=+12.15+ Too much
----------
Can there be 1 large, 3 medium, 1 small?
+2.75+%2B+3%2A2.35+%2B+1.85+=+2.75+%2B+7.05+%2B+1.85+
++2.75+%2B+7.05+%2B+1.85+=+11.65+
They bought 3 medium cones




Numbers_Word_Problems/677682: Concert tickets cost $25 for the balcony and $40 for the first floor. If the total amount collected for 325 tickets was $10,000 how many of each tickets was sold?
What I did was I put it into a equation.
25x+40y=10,000 I don't know if thats right,
and how to solve it after.
1 solutions

Answer 421101 by josmiceli(9679) About Me  on 2012-11-08 16:43:38 (Show Source):
You can put this solution on YOUR website!
You were correct, but you have 2 unknowns and
only 1 equation. The other equation is:
+x+%2B+y+=+325+
Multiply both sides of this equation by +25+
and subtract from the other equation
+25x+%2B+40y+=+10000+
+-25x+-+25y+=+-8125+
+15y+=+1875+
+y+=+125+
and, since
+x+%2B+y+=+325+
+x+%2B+125+=+325+
+x+=+200+
200 balcony tickets were sold
125 1st floor tickets were sold


Quadratic-relations-and-conic-sections/677706: The question says, "Sketch a narrow parabola that spills water and has a turning point of (0,3). Will this parabola have real or complex roots?"
If you could help me please? that would be great, thank you
1 solutions

Answer 421015 by josmiceli(9679) About Me  on 2012-11-08 12:10:16 (Show Source):
You can put this solution on YOUR website!
Plot the point (0,3)
If you make this the vertex ( turning point ) and
the parabola spills water ( does not look like a cup )
then the curve has to cross the x-axis twice and
that makes the roots real, and equally spaced on
either side of the y-axis.
The equation would look like
+graph%28+400%2C+400%2C+-5%2C+5%2C+-5%2C+5%2C+-7x%5E2+%2B+3+%29+


Quadratic-relations-and-conic-sections/677707: The question states, "sketch a parabola with real roots and a turning point of (0,-7). Is the turning point a minimum or maximum value for f(x)?"
thanks
1 solutions

Answer 421012 by josmiceli(9679) About Me  on 2012-11-08 11:57:34 (Show Source):
You can put this solution on YOUR website!
It sounds like it could be either one.
The x-coordinate of the vertex is at
+-b%2F%282a%29+ where the equation looks like
+y+=+ax%5E2+%2B+b%2Ax+%2B+c+
The turning point is at (0,-7), so
+-b%2F%282a%29+=+0+
+b+=+0+
Now I have
+y+=+ax%5E2+%2B+c+
+-7+=+a%2A0%5E2+%2B+c+
+c+=+-7+
------------
It looks like +a+ can be any (+) or (-)
number since it just controls the shape
( narrow or wide ) and the direction
( open down or open up )
I'll say +a+=+3+
+y+=+3x%5E2+-7+ answer
Here's the plot:
+graph%28+400%2C+400%2C+-10%2C+10%2C+-10%2C+10%2C+3x%5E2+-+7+%29+


Numbers_Word_Problems/677693: A pharmacist needs 70 liters of a 50% alcohol solution. She has availble a 30% alcohole solution and an 80% alocohol solution. How many liters of each solution should she mix to obtain 70 liters of wach solution should she mix to obtain 70 liters of a 50% alcohol solution?
1 solutions

Answer 421008 by josmiceli(9679) About Me  on 2012-11-08 11:39:34 (Show Source):
You can put this solution on YOUR website!
Let +a+ = liters of 30% solution needed
Let +b+ = liters of 80% solution needed
given:
(1) +a+%2B+b+=+70+
(2) +%28+.3a+%2B+.8b+%29+%2F+70+=+.5+
-------------------------
(2) +.3a+%2B+.8b+=+.5%2A70+
(2) +.3a+%2B+.8b+=+35+
(2) +3a+%2B+8b+=+350+
Multiply both sides of (1) by +3+ and
subtract (1) from (2)
(2) +3a+%2B+8b+=+350+
(1) +-3a+-+3b+=+-210+
+5b+=+140+
+b+=+28+
and, since
(1) +a+%2B+b+=+70+
(1) +a+%2B+28+=+70+
(1) +a+=+42+
42 liters of 30% solution are needed
28 liters of 80% solution are needed
check answer:
(2) +%28+.3%2A42+%2B+.8%2A28+%29+%2F+70+=+.5+
(2) +%28+12.6+%2B+22.4+%29+%2F+70+=+.5+
(2) +35+=+.5%2A70+
(2) +35+=+35+
OK


Polynomials-and-rational-expressions/677673: find the vertex of the parabola
F(x)=2x^2+8x+3
Can you please show the work so that I can get a full understanding.
Thank you
1 solutions

Answer 421002 by josmiceli(9679) About Me  on 2012-11-08 11:23:51 (Show Source):
You can put this solution on YOUR website!
+F%28x%29=2x%5E2%2B8x%2B3+
This is a parabola with a minimum and not a maximum
I can tell because the squared term is positive. If I changed it
to +F%28x%29=-2x%5E2%2B8x%2B3+ then it would have a maximum.
The vertex is the (x,y) point at the minimum ( or maximum )
---------------
The x-coordinate of the vertex occurs halfway
between the roots, which are
the two solutions to +2x%5E2%2B8x%2B3+=+0+
---------------
To get a deeper understanding of this look at the
quadratic formula which gives these two solutions
---------------
+x%5B1%5D+=+%28-b+%2B+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%29+
+x%5B2%5D+=+%28-b+-+sqrt%28+b%5E2+-+4%2Aa%2Ac+%29%29+%2F+%282%2Aa%29+
Now I'll separate the terms in each solution:
+x%5B1%5D+=+-b%2F%282a%29+%2B+%28+sqrt%28+b%5E2+-+4%2Aa%2Ac%29+%29+%2F+%282%2Aa%29+
+x%5B2%5D+=+-b%2F%282a%29+-+%28+sqrt%28+b%5E2+-+4%2Aa%2Ac%29+%29+%2F+%282%2Aa%29+
-----------------------------------------
Now what you have is:
+x%5B1%5D+ = ( x coordinate of the vertex ) + ( the positive correction )
+x%5B2%5D+ = ( x coordinate of the vertex ) - ( the negative correction )
-------------------
So, you can see that +-b%2F%282a%29+ is the x-coordinate of the vertex
when the form of the equation is +f%28x%29+=+ax%5E2+%2B+b%2Ax+%2B+c+
-------------------
I can apply this to your problem
+F%28x%29=2x%5E2%2B8x%2B3+
+a+=+2+
+b+=+8+
+c+=+3+
+-b%2F%282a%29+=+-8%2F%282%2A2%29+
+-b%2F%282a%29+=+-2+
--------------------
Now you know the vertex is at ( -2, y ). To find y, plug +x+=+-2+
into the equation
+y+=2%2A%28-2%29%5E2%2B8%2A%28-2%29%2B3+
+y+=+2%2A4+-+16+%2B+3+
+y+=+8+-+16+%2B+3+
+y+=+-5+
---------------
The vertex is at ( -2, -5 )
Here's a plot of the equation:
+graph%28+400%2C+400%2C+-7%2C+7%2C+-7%2C+7%2C+2x%5E2+%2B+8x+%2B+3+%29+
The vertex is where is should be




Age_Word_Problems/677530: Ryan is three more than three times the age of Samantha. The sum of their ages is 23. Find the age of both.
1 solutions

Answer 420938 by josmiceli(9679) About Me  on 2012-11-08 00:11:48 (Show Source):
You can put this solution on YOUR website!
+r+%2B+s+=+23+
+r+=+3s+%2B+3+
-------------
By substitution:
+3s+%2B+3+%2B+s+=+23+
+4s+=+20+
+s+=+5+
and, since
+r+%2B+s+=+23+
+r+%2B+5+=+23+
+r+=+18+
Ryan is 18 and
Sam is 5


Rate-of-work-word-problems/677555: a small pump can pump all of the blood out of an average turnip in 30 minutes. a larger pump can pump all of the blood from the same turnip in 20 minutes. If both pumps are hooked to the turnip, then how long would it take to get all of the blood out?

I don't know where to start.
1 solutions

Answer 420936 by josmiceli(9679) About Me  on 2012-11-08 00:05:49 (Show Source):
You can put this solution on YOUR website!
Add the rates of pumping to get the rate
pumping together
( blood pumped by small pump ) / ( pumping time ) + ( blood pumped by large pump ) / ( pumping time )
= ( blood pumped with both pumps ) / ( pumping time )
------------------------------
+1%2F30+%2B+1%2F20+=+1%2Ft+
Multiply both sides by +60t+
+2t+%2B+3t+=+60+
+5t+=+60+
+t+=+12+
It will take 12 minutes with both pumps hooked up


Polynomials-and-rational-expressions/677539: norma can row her boat 12 miles in the same time as it takes Marietta to cover 36 miles in her motorboat. if marietta's boat travels 15mph faster than norma's boat, then how fast is norma rowing her boat.
I know i have to use time=rate divided by distance. I just have no idea where to start.

1 solutions

Answer 420935 by josmiceli(9679) About Me  on 2012-11-07 23:56:59 (Show Source):
You can put this solution on YOUR website!
You need 2 equations- one for Norma
and one for Marietta
Let +t+ = time for both
Let +s+ = the speed of Norma's boat
+s+%2B+15+ = speed of Marietta's boat
---------------------------------
Norma's equation:
(1) +12+=+s%2At+
Marietta's equation:
(2) +36+=+%28+s+%2B+15+%29%2At+
---------------------
(2) +36+=+s%2At+%2B+15t+
Substitute (1) into (2)
(2) +36+=+12+%2B+15t+
(2) +15t+=+24+
(2) +t+=+1.6+
and, since
(1) +12+=+s%2At+
(1) +12+=+s%2A1.6+
(1) +s+=+7.5+
Norma is rowing at 7.5 mi/hr
check:
(2) +36+=+%28+s+%2B+15+%29%2At+
(2) +36+=+%28+7.5+%2B+15+%29%2At+
(2) +36+=+22.5%2At+
(2) +t+=+36%2F22.5+
(2) +t+=+1.6+
OK


Mixture_Word_Problems/677519: Bitches do u know the answer for u suck?
1 solutions

Answer 420932 by josmiceli(9679) About Me  on 2012-11-07 23:43:54 (Show Source):
You can put this solution on YOUR website!
kcu suro frews naehj two nkuods ehc tiB


Mixture_Word_Problems/677541: a chemist added 2liters of water to 8 liters of 48% nitric acid solution. what is the concentration of the new solution
1 solutions

Answer 420930 by josmiceli(9679) About Me  on 2012-11-07 23:34:24 (Show Source):
You can put this solution on YOUR website!
+.48%2A8+=+3.84+ liter of nitric acid in 48% solution
The concentration is:
+3.84+%2F+%28+2+%2B+8+%29+=+3.84+%2F+10+
+3.84%2F10+=+.348+
The concentration is 34.8%


Proportions/677475: Rob can make 2 seats in 11 mins. how long will it take for him to make 16 seats.
NEEDS TO BE WRITTEN AS A PROPORTION!!!!!!!!!!!!!!!!!!
1 solutions

Answer 420889 by josmiceli(9679) About Me  on 2012-11-07 20:51:18 (Show Source):
You can put this solution on YOUR website!
( seats made ) / ( time to make them ) = ( seats made ) / ( time to make them )
+2+%2F+11+=+16+%2F+t+
Multiply both sides by +11t+
+2t+=+11%2A16+
+2t+=+176+
+t+=+88+ min
-------------
You can also solve this way:
it will take him half as long to make just 1 seat
or +11%2F2+=+5.5+ min
16 seats will take him 16 times as long, or
+16%2A5.5+=+88+ min


Quadratic_Equations/677461: How do I graph the quadratic equation x^2+6x+6=0?
1 solutions

Answer 420887 by josmiceli(9679) About Me  on 2012-11-07 20:44:35 (Show Source):
You can put this solution on YOUR website!
actually, you can't graph +x%5E2+%2B+6x+%2B+6+=+0+
It is an equation, but it doesn't relate 2 variables.
What you really mean is +y+=+x%5E2+%2B+6x+%2B+6+
Here's the plot:
+graph%28+400%2C+400%2C+-8%2C+8%2C+-8%2C+8%2C+x%5E2+%2B+6x+%2B+6+%29+
Now if you want to find the roots,
+x%5E2+%2B+6x+%2B+6+=+0+ is what you
+x%5E2+%2B+6x+%2B+%286%2F2%29%5E2+=+-6+%2B+%286%2F2%29%5E2+
+x%5E2+%2B+6x+%2B+9+=+-6+%2B+9+
+%28+x+%2B+3+%29%5E2+=+%28+sqrt%283%29+%29%5E2+
+x+%2B+3+=+sqrt%283%29+
+x+=+-3+%2B+sqrt%283%29+
and
+x+=+-3+-+sqrt%283%29+
------------------
In decimals:
+x+=+-3+%2B+1.732+
+x+=+-1.268+
and
+x+=+-3+-+1.732+
+x+=+-4.732+
These values match up OK with the x-intercepts ( roots )



Age_Word_Problems/677441: A father is 26 years older than his daughter. In four years he will be 2 more than 5 times her age. Find each of their current ages.
1 solutions

Answer 420877 by josmiceli(9679) About Me  on 2012-11-07 20:23:04 (Show Source):
You can put this solution on YOUR website!
Let +d+ = the Daughter's age now
+d+%2B+26+ is the Father's age now
+d+%2B+4+ = the Daughter's age in +4+ years
+5%2A%28+d+%2B+4+%29+%2B+2+ = the Father's age in +4+ years
------------------
The thing about ages is that the difference between
their ages will always remain the same, +26+ years, so
+5%2A%28+d+%2B+4+%29+%2B+2+-+%28+d+%2B+4+%29+=+26+
+5d+%2B+20+%2B+2+-+d+-+4+=+26+
+4d+=+26+-+20+-+2+%2B+4+
+4d+=+8+
+d+=+2+
+d+%2B+26+=+2+%2B+26+
+d+%2B+26+=+28+
The Daughter's age is 2 now
The Father's age is 28 now
check:
+5%2A%28+d+%2B+4+%29+%2B+2+-+%28+d+%2B+4+%29+=+26+
+5%2A%28+2+%2B+4+%29+%2B+2+-+%28+2+%2B+4+%29+=+26+
+5%2A6+%2B+2+-+6+=+26+
+32+-+6+=+26+
+32+=+32+
OK


Mixture_Word_Problems/677444: a fishing boat radioed the coast guard for a helicopter to pick up a sick crew member. at the time of the message the boat is 660 km from the helicopter and heading toward it. the average speed of the boat is 30 km per hour and the average speed of the helicopter is 300 km per hr. how long will it take the helicopter to reach the boat?
1 solutions

Answer 420870 by josmiceli(9679) About Me  on 2012-11-07 20:00:32 (Show Source):
You can put this solution on YOUR website!
Think of the boat as standing still and the
helicopter approaching at the sum of their speeds
+660+=+%28+300+%2B+30+%29%2At+
+660+=+330t+
+t+=+2+
The helicopter will take 2 hrs


Rational-functions/677288: Joe gets from his house to a restaurant by canoeing two miles and then driving 1 mile. He canoes 50 MPH slower than he drives.
A.) Write a rational function that represents his time getting from home to the restaurant. Define your variables.
B.) If he can canoe at 3 MPH, how long will the trip take?
1 solutions

Answer 420867 by josmiceli(9679) About Me  on 2012-11-07 19:55:55 (Show Source):
You can put this solution on YOUR website!
Let +t+%5B1%5D+ = time spent canoeing
Let +t%5B2%5D+ = time spent driving
Let +s+ = his speed driving
+t%5B1%5D+%2B+t%5B2%5D+=+2%2F%28+s+-+50+%29+%2B+1%2Fs+
(a)
+t+=+t%5B1%5D+%2B+t%5B2%5D+
+t%28s%29++=+2%2F%28+s-50+%29+%2B+1%2Fs+
------------------------
(b)
+s+-+50+=+3+
+s+=+53+
+t%28s%29++=+2%2F%28+53-50+%29+%2B+1%2F53+
+t%28s%29+=+2%2F3+%2B+1%2F53+
+t%28s%29+=+.6667+%2B+.01887+
+t%28s%29+=+.68557+
+.68557%2A60+=+41.134+
The trip will take 41.1 minutes




Age_Word_Problems/677282: There are four brothers in a store. Each brother is two years older than the next. The youngest brother is three times as young as the older brother. What is the age of the brothers?
1 solutions

Answer 420808 by josmiceli(9679) About Me  on 2012-11-07 16:20:57 (Show Source):
You can put this solution on YOUR website!
Let +x+ = the age of the youngest brother
The other brothers are:
+x+%2B+2+
+x+%2B+4+
+x+%2B+6+
+x+%2B+6+=+3x+
--------------
+2x+=+6+
+x+=+3+
+x+%2B+2+=+5+
+x+%2B+4+=+7+
+x+%2B+6+=+9+
-------------
The brother's are 3,5,7, and 9


Numeric_Fractions/677284: baking - a recipe for a loaf of banana bread requires 2/3 cup of vegetable oil. You have 3 cups of oil.How many loaves of banana bread can u make with the oil?
1 solutions

Answer 420805 by josmiceli(9679) About Me  on 2012-11-07 16:15:19 (Show Source):
You can put this solution on YOUR website!
Set up the ratio:
( 1 loaf of banana bread ) / ( 2/3 cup oil ) = ( x loaves banana bread ) / ( 3 cups oil )
+1+%2F+%282%2F3%29+=+x+%2F+3+
+3%2F2+=+x%2F3+
Multiply both sides by +6+
+9+=+2x+
+x+=+4.5+
You can make 4 and 1/2 loaves of banana bread with 3 cups of oil


Money_Word_Problems/677182: Randy Invested twice as much at 10% as he did at 8%. If he earned $30.80 annually, how much did he invest at each rate?
1 solutions

Answer 420739 by josmiceli(9679) About Me  on 2012-11-07 13:42:46 (Show Source):
You can put this solution on YOUR website!
Let +x+ = amount invest @ 8%
+2x+ = amount invested @ 10%
given:
+.08x+%2B+.1%2A%282x%29+=+30.8+
+.08s+%2B+.2x+=+30.8+
+.28x+=+30.8+
+x+=+110+
+2x+=+220+
Randy invested $110 @8% and $220 @10%


Numbers_Word_Problems/677140: Jim lives 70 miles from work. He rides his bike at 6 mph to the metro station. He then takes the metro to work, which travels at 59 mph. If he spends 45 minutes more on the bike than on the metro, what is the distance from his work to the metro station?
This is the kind of word problem I have had the most trouble conceptualizing in my mind. Firstly, its out to convert minutes to time, so I've attempted this, below. The formula should be D=RT,because they I'm being asked to solve the distance. In my set up, I put 49 minutes over 60 minutes to represent minutes over hours.
6(x + 49/60) + 59x = 70
I then distributed the left side and converted the fraction into a decimal by dividing 49 into 60. My calculator said .816. I assumed I should round my answer to the nearest tenth (is that something I should be doing?), because I get two answers. With .816, I get 6 x .816 = 4.896, with .81, I get 6 x .81 = 4.86 and with the rounded to the nearest tenth, I 6 x .85 = 5.1 THREE completely different answers! So, I'll stick with .81 to see what happens.
6x + 4.86 +59x = 70
Next, I combine like terms.
65x = 65.14
Lastly I divide the variable on both sides.
On my calculator, it says the total is 1.0
x = 1.0
Then, I plugged 1.0 into the metro 59x to make 59(1.0) = and I got 59.
This doesn't seem right to me. Can you help me find out what it is I need to know?

1 solutions

Answer 420738 by josmiceli(9679) About Me  on 2012-11-07 13:37:10 (Show Source):
You can put this solution on YOUR website!
Just call 45 min 3/4 hr
You need 2 equations, one for home to Metro
and one for Metro to work
Let +d+ = the distance from Metro to work
+70+-+d+ = the distance from home to Metro
Let +t+ = time spent on Metro
+t+%2B+3%2F4+ = time spent on bike ( home to metro )
-------------------
Equation for home to Metro:
(1) +70+-+d+=+6%2A%28+t+%2B+3%2F4+%29+
Equation for Metro to work:
(2) +d+=+59t+
---------------
(1) +70+-+d+=+6t+%2B+9%2F2+
Substitute (2) into (1)
(1) +70+-+59t+=+6t+%2B+9%2F2+
(1) +59t+%2B+6t+=+70+-+9%2F2+
(1) +65t+=+65.5+
(1) +t+=+1.00769+ hrs
and
(2) +d+=+59t+
(2) +d+=+59%2A%2865.5%2F65%29+
(2) +d+=+3835+%2F+65.5+
(2) +d+=+59.454+
From work to Metro is 59.454 mi
check answer:
(2) +d+=+59t+
(2) +59.454+=+59t+
(2) +t+=+59.454+%2F+59+
(2) +t+=+1.0077+
and
(1) +70+-+d+=+6%2A%28+t+%2B+3%2F4+%29+
(1) +70+-+d+=+6%2A%28+1.0077+%2B+.75+%29+
(1) +70+-+d+=+6%2A1.7577+
(1) +d+=+70+-+10.546+
(1) +d+=+59.454+
OK
Hope I got it




Percentage-and-ratio-word-problems/677041: The numerator of a fraction is 3 less than the denominator. If 5 is added to both the numerator and denominator, the value resulting fraction is 3/4. Find the original fraction
1 solutions

Answer 420653 by josmiceli(9679) About Me  on 2012-11-07 04:55:42 (Show Source):
You can put this solution on YOUR website!
Let the fraction = +a%2Fb+
given:
(1) +a+=+b+-+3+
(2) +%28+a+%2B+5+%29+%2F+%28+b+%2B+5+%29+=+3%2F4+
-----------------------------
Substitute (1) into (2)
(2) +%28+b+-+3+%2B+5+%29+%2F+%28+b+%2B+5+%29+=+3%2F4+
(2) +%28+b+%2B+2+%29+%2F+%28+b+%2B+5+%29+=+3%2F4+
Multiply both sides by +4%2A%28+b-5+%29+
(2) +4%2A%28+b+%2B+2+%29+=+3%2A%28+b+%2B+5+%29+
(2) +4b+%2B+8+=+3b+%2B+15+
(2) +b+=+7+
and, since
(1) +a+=+b+-+3+
(1) +a+=+7+-+3+
(1) +a+=+4+
The fraction is +a%2Fb+=+4%2F7+
check answer:
(2) +%28+a+%2B+5+%29+%2F+%28+b+%2B+5+%29+=+3%2F4+
(2) +%28+4+%2B+5+%29+%2F+%28+7+%2B+5+%29+=+3%2F4+
(2) +9+%2F+12+=+3%2F4+
(2) +3%2F4+=+3%2F4+
OK