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Average/309823: If the average of three numbers is V. If one of the numbers is Z and another is Y, what is the remaining number?

1 solutions

Answer 221593 by ankor@dixie-net.com(15652) About Me  on 2010-05-30 13:21:11 (Show Source):
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If the average of three numbers is V. If one of the numbers is Z and another is Y, what is the remaining number?
:
Let x = remaining number
:
%28x%2By%2Bz%29%2F3 = V
Multiply both sides by 3
x + y + z = 3V
x = 3V - y - z, is the remaining number


Polynomials-and-rational-expressions/309783: one of two supplementary angles is 4degrees more thatn one -third of the other angle . find the measure of each of the angle
1 solutions

Answer 221572 by ankor@dixie-net.com(15652) About Me  on 2010-05-30 10:42:17 (Show Source):
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one of two supplementary angles is 4 degrees more than one -third of the other angle .
find the measure of each of the angle
:
Let x = one angle
then
(180-x) = the other angle
:
x = 1%2F3(180 - x) + 4
Multiply both sides by 3
3x = 180 - x + 3(4)
3x = 180 - x + 12
3x + x = 192
4x = 192
x = 192%2F4
x = 48 degrees
then
180 - 48 = 132 degrees is the other angle
:
:
See if that fits in the statement;
"one of two supplementary angles is 4 degrees more than one-third of the other"
48 = 1%2F3(132) + 4
48 = 44 + 4


Equations/309748: solve 5 raised to x+2=12?
1 solutions

Answer 221571 by ankor@dixie-net.com(15652) About Me  on 2010-05-30 10:23:31 (Show Source):
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solve 5 raised to x+2=12?
5%5E%28x%2B2%29+=+12+
Use logs here
log%285%5E%28x%2B2%29%29+=+log%2812%29+
log equiv of exponents
(x+2)log(5) = log(12)
x + 2 = log%2812%29%2Flog%285%29
using a calc
x + 2 = 1.544
:
x = 1.544 - 2
;
x = -.456
:
:
Check on a calc enter 5^(-.456+2) = 12.00


Rate-of-work-word-problems/309801: If Sam can do a job in 4 days that Lisa can do in 6 days and Tom can do in 2 days, how long would the job take if Sam, Lisa, and Tom worked together to complete it? What equation do you need to find the answer?
1 solutions

Answer 221570 by ankor@dixie-net.com(15652) About Me  on 2010-05-30 10:12:52 (Show Source):
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If Sam can do a job in 4 days that Lisa can do in 6 days and Tom can do in 2 days,
how long would the job take if Sam, Lisa, and Tom worked together to complete it?
What equation do you need to find the answer?
:
Let x = time required when working together
Let the completed job = 1
:
The equation
t%2F4 + t%2F6 + t%2F2 = 1


Rate-of-work-word-problems/309762: A completes one work in20 days. B cmpletes the same work in 25 days while C completes the same in 30 days. If intially A started the work and after 4 days he quit it. Next B carry forward the work & he copleted the half of the remaining work then how in how many days the C will cmplete the remaining work?
1 solutions

Answer 221569 by ankor@dixie-net.com(15652) About Me  on 2010-05-30 10:09:16 (Show Source):
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A completes one work in 20 days.
B cmpletes the same work in 25 days
while C completes the same in 30 days.
:
If initially A started the work and after 4 days he quits it.
Next B carry forward the work & he completed the half of the remaining work
then how in how many days the C will complete the remaining work?
:
Let the completed work = 1
:
A does 4%2F20 = 1%2F5; 4%2F5 remains
:
B does 1%2F2 * 4%2F5 = 2%2F5 remains
:
C%2F30 = 2%2F5
cross multiply
5C = 60
C = 60%2F5
C = 12 days to complete it
:
:
Check
A does 1%2F5
B does 2%2F5
C does 2%2F5
-----------------
total 1


Rectangles/309709: im trying to figure out how to get The width of a rectangular feed lot is 8 m less
than the length. The area is 20 m squared . Find the length and
the width.
i thought it would be (8-m)((20-m)squared
1 solutions

Answer 221502 by ankor@dixie-net.com(15652) About Me  on 2010-05-29 21:57:40 (Show Source):
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The width of a rectangular feed lot is 8 m less than the length.
The area is 20 m squared .
Find the length and the width.
:
"The width of a rectangular feed lot is 8 m less than the length."
W = (L-8)
:
L * W = 20
Replace W with (L-8), find L
L * (L-8) = 20
A quadratic equation
L^2 - 8L - 20 = 0
factors to
(L-10)*L+2) = 0
The positive solution is what we want here
L = 10 m is the length
then
W = 10 - 8
W = 2 m is the width


Quadratic_Equations/309682: N(x)=0.4x^2+8.8x+11
x=days
Peak sales of tickets will be on what day and how many tickets are sold that day?
1 solutions

Answer 221491 by ankor@dixie-net.com(15652) About Me  on 2010-05-29 19:02:48 (Show Source):
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N(x)=-0.4x^2+8.8x+11 (coefficient of x^2 has to be negative)
x=days
Peak sales of tickets will be on what day and how many tickets are sold that day?
:
This is a quadratic equation, find the axis of symmetry to find the day of max sales
Use the formula: x = -b/(2a), in this equation a=-.4, b=8.8
x = %28-8.8%29%2F%282%2A-.4%29
x = %28-8.8%29%2F%28-.8%29
x = +11th day will be peak sales
:
Find the no. of sales on that day
N(x) = -0.4x^2 + 8.8x + 11
Replace x with 11
N(11) = -0.4(11^2) + 8.8(11) + 11
N(11) = -0.4(121) + 96.8 + 11
N(11) = -48.4 + 96.8 + 11
N(11) = 59.4 ~ 59 tickets sold on the 11th day


Volume/309470: The top of a right rectangular box has an area of 88cm^2
The sides have areas 32cm^2 and 44cm^2 What are the
dimensions of the box?
1 solutions

Answer 221455 by ankor@dixie-net.com(15652) About Me  on 2010-05-29 15:46:21 (Show Source):
You can put this solution on YOUR website!
The top of a right rectangular box has an area of 88cm^2
The sides have areas 32cm^2 and 44cm^2
What are the dimensions of the box?
:
L*W = 88
:
L*H = 32
L = 32%2FH
:
W*H = 44
W = 44%2FH
:
Substitute for L & W in the 1st equation
32%2FH * 44%2FH = 88
1408%2FH%5E2 = 88
88H^2 = 1408
H^2 = 1408%2F88
H^2 = 16
H = sqrt%2816%29
H = 4 cm is the height
:
L = 32%2FH
L = 32%2F4
L = 8 cm is the length
:
I'll let you find W using W = 44%2FH


Age_Word_Problems/309626: Mary (m) is 4 years older than Rico (r). Ten years ago Mary was 3 times as old as Rico was then. a) how old are they now? b) determine if answer is correct by checking that it satisfies the conditions of the problem
I've got r = 4 = m and have to subtract 10 years from both and multiply both by 3?
3(r-10) = m -10
3r - 30 = m -10
m = 3r - 20
r + 4 = 3r -
4 + r = -20 + 3r (subtract 3r from both sides)
4 + -2r = -20 (subtract 4 from both sides)
-2r = -24 (divide both by -2) gives the solution of 12?
so if I was solving for r, then that is Rico's age 10 years ago?? He would be 22 now and if 4 years older, Mary would be 26? This can't be right if 10 years ago she was 3 times his age.




1 solutions

Answer 221444 by ankor@dixie-net.com(15652) About Me  on 2010-05-29 12:56:06 (Show Source):
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Mary (m) is 4 years older than Rico (r).
Write an equation for this statement first:
m = r+4
Ten years ago Mary was 3 times as old as Rico was then.
a) how old are they now?
I've got r = 4 = m?????? and
have to subtract 10 years from both and multiply both by 3?
3(r-10) = m - 10
3r - 30 = m -10
Correct up to here, now
3r = m - 10 + 30
3r = m + 20
Replace m with (r+4)
3r = (r+4) + 20
3r - r = 24
2r = 24
r = 24%2F2
r = 12 yrs is Rico's present age
and we know
m = r + 4
m = 12 + 4
m = 16 yrs is Mary's present age
:
b) determine if answer is correct by checking that it satisfies the conditions of the problem
Check solution in the statement:
" Ten years ago Mary was 3 times as old as Rico was then. "
16 - 10 = 3(12 - 10)
6 = 3(2); confirms the solutions
:
:
Did this help straighten things out for you?


Unit_Conversion_Word_Problems/309544: Multistep word problems
Word problems are more complicated with two or more unknown values. First, assign a variable to each unknown value. The word problem should then be translated into the appropriate number of mathematical equations, which can then be solved by substitution. Keep in mind that the number of mathematical equations needed is equal to the number of variables.
Consider the following multistep word problem:
The sum of the ages of a brother and sister is 25. If four times the brother's age is subtracted from three times the sister's age, the difference is 5.Consider just the first sentence of this multistep word problem.
Sentence 1: The sum of the ages of a brother and sister is 25.
Give an equation that represents this statement using as the age of the brother and as the age of the sister
??????If four times the brother's age is subtracted from three times the sister's age, the difference is 5.Give an equation that represents this statement using b as the age of the brother and s as the age of the sister.

1 solutions

Answer 221443 by ankor@dixie-net.com(15652) About Me  on 2010-05-29 12:35:00 (Show Source):
You can put this solution on YOUR website!
The sum of the ages of a brother and sister is 25. If four times the brother's age is subtracted from three times the sister's age, the difference is 5.Consider just the first sentence of this multi-step word problem.
:
Let b = brother's present age
Let s = sister's present age
:
Sentence 1: The sum of the ages of a brother and sister is 25.
Give an equation that represents this statement using as the age of the brother and as the age of the sister
b + s = 25
:
If four times the brother's age is subtracted from three times the sister's age, the difference is 5.
Give an equation that represents this statement using b as the age of the brother and s as the age of the sister.
3s - 4b = 5
:
Substitution is one way to solve this, rearrange the 1st equation to:
b = (25-s)
:
Substitute (25-s) for b in the 2nd equation
3s - 4(25-s) = 5
3s - 100 + 4s = 5
3s + 4s = 5 + 100
7s = 105
s = 105%2F7
s = 15 yrs is sister's age
then using the equation b = 25-s:
b = 25 - 15
b = 10 yrs is brothers age
;
:
Confirm the solution in the 2nd statement;
"four times the brother's age is subtracted from three times the sister's age, the difference is 5."
3(15) - 4(10) = 5
:
Do you understand this now???


Numbers_Word_Problems/309617: find three positive numbers whose sum is 44 if the second number is twice the first and the third number is two thirds the first.


1 solutions

Answer 221442 by ankor@dixie-net.com(15652) About Me  on 2010-05-29 12:09:38 (Show Source):
You can put this solution on YOUR website!
find three positive numbers whose sum is 44 if the second number is twice the
first and the third number is two thirds the first.
:
x + y + z = 44
:
"the second number is twice the first"
y = 2x
:
"the third number is two thirds the first."
z = 2%2F3x
:
Replace y and z in the 1st equation, find x:
x + 2x + 2%2F3x = 44
3x + 2%2F3x = 44
multiply both sides by 3, results:
9x + 2x = 3(44)
11x = 132
x = 132%2F11
x = 12
then
y = 2(12)
y = 24
and
z = 2%2F3(12)
z = 8
:
:
Check solution: 12 + 24 + 8 = 44


logarithm/309405: I'm new to logs and I'm not sure how to answer these questions:
(any help would be greatly appreciated, thanks :D )
1) log(base4) (x^2 - 3) + log(base 4) 10 = 1
2) log(base 5)3 - log(base 5) 5x = 2
3) ln (x+7) + ln (x+3) = ln 77
4) ln (x+2) - ln (x-1) = 1

1 solutions

Answer 221387 by ankor@dixie-net.com(15652) About Me  on 2010-05-28 20:32:32 (Show Source):
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1) log(base4) (x^2 - 3) + log(base 4) 10 = 1
addition of logs is the same as multiply so we can write it:
log4(10*(x^2-3)) = 1
log4(10x^2 - 30) = 1
Write the exponent equiv of logs
4^1 = 10x^2 - 30
4 = 10x^2 - 30
4 + 30 = 10x^2
34 = 10x^2
x^2 = 34/10
x^2 = 3.4
x = sqrt%283.4%29
x = 1.844
:
2) log(base 5)3 - log(base 5) 5x = 2
subtracting logs is the same as divide so we can write it
log5%283%2F%285x%29%29+=+2
exponent equiv
5^2 = 3%2F%285x%29
25 = 3%2F%285x%29
Multiply by 5x
25(5x) = 3
125x = 3
x = 3%2F125
:
:
3) ln (x+7) + ln (x+3) = ln 77
ln((x+7)*(x+3)) = ln(77)
FOIL
ln((x^2+10x+21) = ln(77)
same as
x^2 + 10x + 21 = 77
x^2 + 10x + 21 - 77 = 0
A quadratic equation
x^2 + 10x - 56 = 0
Factors to
(x-14)(x-4) = 0
only the positive solution can be used here
x = 4
:
4) ln (x+2) - ln (x-1) = 1
ln%28%28x%2B2%29%2F%28x-1%29%29+=+1
find the e^ of both sides
%28x%2B2%29%2F%28x-1%29 = 2.71828
x + 2 = 2.71828(x-1)
x + 2 = 2.71828x - 2.71828
2.71828 + 2 = 2.71828x - x
4.71828 = 1.71828x
x = 4.71828/1.71828
x = 2.746


Human-and-algebraic-language/309519: My son who is in 4th grade needs help with this problem:
Mr. Herman had $125, and Mr. Chandra had $80. After each of them had paid for a concert ticket, Mr. Herman had six times as much money as Mr. Chandra.
How much money did Mr. Chandra have left?

1 solutions

Answer 221374 by ankor@dixie-net.com(15652) About Me  on 2010-05-28 18:58:00 (Show Source):
You can put this solution on YOUR website!
Mr. Herman had $125, and Mr. Chandra had $80.
After each of them had paid for a concert ticket, Mr. Herman had six times as much money as Mr. Chandra.
How much money did Mr. Chandra have left?
:
Let x = cost of the ticket
125 - x = 6(80-x)
125 - x = 480 - 6x
-x + 6x = 480 - 125
5x = 355
x = 355%2F5
x = $71 is cost of ticket
then
80 - 71 = $9, Mr C had left
:
Check solution in the original equation
125 - 71 = 6(9)


Surface-area/309443: The volume of an open box with a square base and rectangular sides us 250 cubed inches. if sides are double thickness and the bottom is triple thickness, what size box will use the least amount of material?
1 solutions

Answer 221371 by ankor@dixie-net.com(15652) About Me  on 2010-05-28 18:35:50 (Show Source):
You can put this solution on YOUR website!
The volume of an open box with a square base and rectangular sides us 250 cubed inches.
if sides are double thickness and the bottom is triple thickness, what size box will use the least amount of material?
:
Surface area of an open box with a square base
x = side of the square base
h = height of the box
S.A = x^2 + 4(x*h)
:
Surface area required with a triple thickness bottom and double thickness sides
S.A. = 3x^2 + 8(x*h)
:
Vol = x^2*h
x^2*h = 250
h = 250%2Fx%5E2
:
S.A = 3x^2 + 8(x*h)
Substitute for h
S.A. = 3x^2 + 8(x*250%2Fx%5E2)
S.A. = 3x^2 + 8(250%2Fx)
S.A. = 3x^2 + 2000%2Fx
:
Plot this equation
+graph%28+300%2C+200%2C+-6%2C+16%2C+-200%2C+1000%2C+3x%5E2+%2B+%282000%2Fx%29+%29+
You can see min material for surface area occurs when x = 7
Find the height
h = 250%2F7%5E2
h = 5.1 inches
:
Least amt of material used in a 7 by 7 by 5.1 inch box
:
:


Rate-of-work-word-problems/309458: a,b, andc can finish a job in 6 days. if b and c work together, the job will take 9 days;if a and c work together, the job will be done in 8 days. in how many days can each man working alone do the job?
1 solutions

Answer 221332 by ankor@dixie-net.com(15652) About Me  on 2010-05-28 16:19:54 (Show Source):
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a, b, and c can finish a job in 6 days.
if b and c work together, the job will take 9 days;
if a and c work together, the job will be done in 8 days.
in how many days can each man working alone do the job?
:
Let the completed job = 1
:
"a, b, and c can finish a job in 6 days."
1.6%2Fa + 6%2Fb + 6%2Fc = 1
:
"if b and c work together, the job will take 9 days;"
2.9%2Fb + 9%2Fc = 1
:
"if a and c work together, the job will be done in 8 days."
3.8%2Fa + 8%2Fc = 1
:
Multiply eq1 by 3, and eq2 by 2
18%2Fa + 18%2Fb + 18%2Fc = 3
0%2Fa + 18%2Fb + 18%2Fc = 2
--------------------------subtraction eliminates a & b, find c
18/a = 1
Mult both sides by a
a = 18 hrs alone
:
replace a with 18 in eq3, find c
8%2F18 + 8%2Fc = 1
Multiply by 18c
8c + 18(8) = 18c
8c + 144 = 18c
144 = 18c - 8c
144 = 10c
c = 144%2F10
c = 14.4 hrs alone
:
replace c with 14.4 in eq2, find b
9%2Fb + 9%2F14.4 = 1
multiply by 14.4b
14.4(9) + 9b = 14.4b
129.6 = 14.4b - 9b
129.6 = 5.4b
b = 129.6%2F5.4
b = 24 hrs alone
:
solution: a=18 hrs, b=24 hrs, c= 14.4 hrs
:
See if that flies in the eq1
6%2F18 + 6%2F24 + 6%2F14.4
.333 + .25 + .417 = 1





Travel_Word_Problems/309461: a person traveling 4 hr by plane and 25 hr by ship covers 1580 miles. if the speed of the plane had been one-half of the actual speed and the speed of the ship had been one-forth greater, the person would have traveled only 1315 miles in the same length of time. find the speeds of both the plane and the ship.
1 solutions

Answer 221316 by ankor@dixie-net.com(15652) About Me  on 2010-05-28 15:29:54 (Show Source):
You can put this solution on YOUR website!
A person traveling 4 hr by plane and 25 hr by ship covers 1580 miles.
If the speed of the plane had been one-half of the actual speed and the speed
of the ship had been one-forth greater, the person would have traveled only
1315 miles in the same length of time.
Find the speeds of the plane and the ship.
:
Let x = speed of plane
and
Let y = speed of shipe
:
Two distance equations; dist = time * speed
:
4x + 25y = 1580
and
4(.5x) + 25(1.25y) = 1315
2x + 31.25y = 1315
:
Multiply above equation by 2. Subtract the first equation
4x + 62.5y = 2630
4x + 25y = 1580
---------------------subtraction eliminates x, find y:
37.5y = 1050
y = 1050%2F37.5
y = 28 mph speed of the ship
:
Find x using the 1st equation
4x + 25(28) = 1580
4x + 700 = 1580
4x = 1580 - 700
4x = 880
x = 880%2F4
x = 220 mph speed of the plane
:
:
Check solution in 2nd equation where plane speed = 110 and boat speed = 35:
4(110) + 25(35) =
440 + 875 = 1315


Surface-area/309326: A farmer has a square plot of land. An irrigation system can be installed with the option of one large circular sprinkler, or nine small sprinklers. The farmer wants to know which plan will provide water to the greatest percentage of land in the field, regardless of the cost and the watering pattern.”
1 solutions

Answer 221314 by ankor@dixie-net.com(15652) About Me  on 2010-05-28 15:19:31 (Show Source):
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A farmer has a square plot of land.
An irrigation system can be installed with the option of one large circular sprinkler, or nine small sprinklers.
The farmer wants to know which plan will provide water to the greatest
percentage of land in the field, regardless of the cost and the watering pattern.”
:
We can use an example. Assume a square field 90' on a side
:
then diameter of circular area will be 90' also. r = 45
A = pi%2A45%5E2
A = 6362 sq/ft
:
Using 9 circular sprinklers, each would have a diameter of 30'. r = 15
A = pi%2A15%5E2%2A9
A = 6362 sq/ft Also!!


Square-cubic-other-roots/309426: Can you help me with this word problem?
Landing speed and weight. Because the gross weight
of the Piper Cheyenne depends on how much fuel and
cargo are on board, the proper landing speed
is not always the same. The formula
V =√1.496L gives the landing speed in terms of
the gross weight only.
a) Find the landing speed if the gross weight is 7000 lb.
b) What gross weight corresponds to a landing speed of
115 ft/sec?

1 solutions

Answer 221312 by ankor@dixie-net.com(15652) About Me  on 2010-05-28 14:49:37 (Show Source):
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Landing speed and weight.
Because the gross weight of the Piper Cheyenne depends on how much fuel and
cargo are on board, the proper landing speed is not always the same.
:
The formula V =sqrt%281.496L%29 gives the landing speed in terms of the gross weight only.
:
a) Find the landing speed if the gross weight is 7000 lb.
replace L with 7000
V =sqrt%281.496%287000%29%29
:
V =sqrt%2810472%29
V = 102.33 ft/sec
:
b) What gross weight corresponds to a landing speed of 115 ft/sec?
sqrt%281.496L%29 = 115
Square both sides
1.496L = 13225
L = 13225%2F1.496
L = 8,840.24 lb gross weight


Miscellaneous_Word_Problems/309433: I think I got the equation right to solve this word problem: You drive to California. On the way, you averaged 10 miles per hour less, and the drive took you 5 extra hours. What was your average speed on thw\e way to California?
This is the formula I used but not sure how to solve it:
1500=(R-10)(T+5)
1 solutions

Answer 221308 by ankor@dixie-net.com(15652) About Me  on 2010-05-28 14:23:38 (Show Source):
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You drive to California. On the way, you averaged 10 miles per hour less, and the drive took you 5 extra hours. What was your average speed on thw\e way to California?
:
I would do it this way:
:
Let r = speed on the way to Calif
then
(r+10) = speed on the return trip
:
Let 1500 mi = one way distance
:
Write a time equation; time = dist/speed
to Calif time - return time = 5 hrs
1500%2Fr - 1500%2F%28r%2B10%29 = 5 hrs
:
multiply by r(r+10), results:
1500(r+10) - 1500r = 5r(r+10)
1500r + 15000 - 1500r = 5r^2 + 50r
:
Combine on the right
0 = 5r^2 + 50r - 15000
:
simplify, divide by 5, results
r^2 + 10r - 3000 = 0
:
Factors to
(r+60)(r-50) = 0
:
the positive solution is what we want here
r = 50 mph is the speed to Calif
:
:
Check solutions by finding the times: (return trip speed = 60 mph)
1500/50 = 30 hrs
1500/60 = 25 hrs
----------------
time dif: 5 hrs



Travel_Word_Problems/309424: A plane averaged 158 km/h. On the returned trip the plane only averaged 112 km/h. While flying back into the same wind, find the speed of the wind and of the plane in still air.
1 solutions

Answer 221305 by ankor@dixie-net.com(15652) About Me  on 2010-05-28 13:58:21 (Show Source):
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A plane averaged 158 km/h. On the returned trip the plane only averaged 112 km/h.
While flying back into the same wind,
find the speed of the wind and of the plane in still air.
:
Let s = speed of the plane in still air
Let w = speed of the wind
From the given information we can write two equation
s + w = 158
s - w = 112
-------------Addition eliminates w, find s
2s = 270
s = 135 km/hr in still air
Find w
135 + w = 158
w = 158 - 135
w = 23 km/hr is the wind
:
Check in "against the wind" equation
135 - 23 = 112


Travel_Word_Problems/309272: You drive 220 miles to see a friend. The return trip takes 20 minutes less than the original trip, and your average speed is 5 miles per hour faster. What is your average speed on the return trip?
1 solutions

Answer 221180 by ankor@dixie-net.com(15652) About Me  on 2010-05-27 22:00:38 (Show Source):
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You drive 220 miles to see a friend.
The return trip takes 20 minutes less than the original trip, and your average speed is 5 miles per hour faster.
What is your average speed on the return trip?
:
Let s = return trip speed
then
(s-5) = original trip speed
:
Change 20 min to 1/3 hr
:
Write a time equation, Time = dist/speed
Original trip time - return trip time = 1/3 hr
220%2F%28s-5%29 - 220%2Fs = 1%2F3
multiply equation by 3s(s-5) results:
3s(220) - 3(s-5)*220 = s(s-5)
660s - 660(s - 5) = s^2 - 5s
660s - 660s + 3300 = s^2 - 5s
0 = s^2 - 5s - 3300
Factors to
(s-60)(s+55) = 0
s = +60 mph


Polynomials-and-rational-expressions/308985: Simplify if possible
+%282x%29%2F%282x%5E2+-+7x+%2B+3%29+-+%28x%29%2F%28x%5E2+-+9%29+
1 solutions

Answer 221068 by ankor@dixie-net.com(15652) About Me  on 2010-05-27 16:43:42 (Show Source):
You can put this solution on YOUR website!
+%282x%29%2F%282x%5E2+-+7x+%2B+3%29+-+%28x%29%2F%28x%5E2+-+9%29+
Factor the denominators
+%282x%29%2F%28%282x-1%29%28x-3%29%29+-+%28x%29%2F%28%28x-3%29%28x%2B3%29%29+
Over the common denominator
+%282x%28x%2B3%29+-+x%282x-1%29%29%2F%28%282x-1%29%28x-3%29%28x%2B3%29%29 = +%28%282x%5E2%2B6x-2x%5E2%2Bx%29%29%2F%28%282x-1%29%28x-3%29%28x%2B3%29%29 = +%28%287x%29%29%2F%28%282x-1%29%28x-3%29%28x%2B3%29%29


Volume/309025: find the total number of bowling balls with a radius of 3.25" that can fit on the four shelves. The shelving unit is 30" long, 8" wide and 24" high. the bottom shelf is 3" high and the other three are 6" high. Please help! thanks
1 solutions

Answer 221065 by ankor@dixie-net.com(15652) About Me  on 2010-05-27 16:09:24 (Show Source):
You can put this solution on YOUR website!
find the total number of bowling balls with a radius of 3.25" that can fit on the four shelves.
The shelving unit is 30" long, 8" wide and 24" high. the bottom shelf is 3" high and the other three are 6" high.
:
A ball with a 3.25' radius has a diameter of 6.5" (height of the ball).
That won't fit on any of the shelves. the answer is 0 balls


Numeric_Fractions/309190: I don't know how to do this I really need help, someone pacient and friendly please! Thank-you.
1 solutions

Answer 221051 by ankor@dixie-net.com(15652) About Me  on 2010-05-27 15:35:00 (Show Source):


Linear-equations/309034: I need help and real confused. Find the value of x ... f(x) = -1/2x +6
1 solutions

Answer 221049 by ankor@dixie-net.com(15652) About Me  on 2010-05-27 15:33:25 (Show Source):
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f(x) = 1%2F2x + 6
Find x when f(x) = 0
1%2F2x + 6 = 0
:
1%2F2x = -6
Multiply both sides by 2
x = -12


Average/309108: A total of 50 juniors & seniors were given a math test. The 35 juniors attained an average score of 80 while the 15 seniors attained an average of 70. What was the average score for all 50 students that took the test?
I dont understand how.. to get the answer
1 solutions

Answer 221048 by ankor@dixie-net.com(15652) About Me  on 2010-05-27 15:27:39 (Show Source):
You can put this solution on YOUR website!
A total of 50 juniors & seniors were given a math test.
The 35 juniors attained an average score of 80 while the 15 seniors attained an average of 70.
What was the average score for all 50 students that took the test?
:
Av = %28%2835%2880%29+%2B+15%2870%29%29%29%2F50


Linear-equations/309180: Please help!!
The answer is 19.. I just don't know how to get it. I keep getting 18 as an answer.
A construction company spent 26 hours on two jobs. One job took 5 more the twice the number of hours of the other. How long did the larger job take?

Thank you so much for your help!!
Rebecca
1 solutions

Answer 221046 by ankor@dixie-net.com(15652) About Me  on 2010-05-27 15:23:49 (Show Source):
You can put this solution on YOUR website!
A construction company spent 26 hours on two jobs.
One job took 5 more the twice the number of hours of the other.
How long did the larger job take?
:
Let x = time for larger job
Let y = time for the other job
:
"A construction company spent 26 hours on two jobs."
x + y = 26
y = (26-x); this form for substitution
:
"One job took 5 more the twice the number of hours of the other."
x = 2y + 5
:
How long did the larger job take?
Replace y with (26-x) in the above equation
x = 2(26-x) + 5
x = 52 - 2x + 5
x + 2x = 52 + 5
3x = 57
x = 57%2F3
x = 19 hrs
:
:
Check solution; y = 26-19 = 7 hrs
"One job took 5 more the twice the number of hours of the other."
19 = 2(7) + 5


Quadratic_Equations/308990: assume that you sell 65 sandwiches for $1 each. if you lose 8 customers each time you raise the price $.10 what is the price that will produce the greatest amount of sales? what is the amount of revenue that you will bring in? solve using quadratics
1 solutions

Answer 221027 by ankor@dixie-net.com(15652) About Me  on 2010-05-27 13:46:33 (Show Source):
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assume that you sell 65 sandwiches for $1 each. if you lose 8 customers each time you raise the price $.10 what is the price that will produce the greatest amount of sales? what is the amount of revenue that you will bring in? solve using quadratics
:
Let x = no. of .10 increases & no. of 8 customer decreases
:
Revenue = price * no. sold
R(x) = (1 + .10x)(65 - 8x)
FOIL
R(x) = 65 - 8x + 6.5x - .8x^2
R(x) = 65 - 1.5x - .8x^2
A quadratic equation
y = -.8x^2 - 1.5x + 65
Find the axis of symmetry; x = -b/(2a), a=-.8, b=-1.5
x = %28-%28-1.5%29%29%2F%282%2A-.8%29
x = %281.5%29%2F%28-1.6%29
x = -.9375; a negative value means any .10 increase makes you lose money


Rational-functions/308975: Suppose that x and y vary inversely and that y=1/6 when x=3. Write a function that models the inverse variation and find y when x=10.
a) +y=1%2F2x+ ; +1%2F20+
b) +y=1%2F6x+ ; +1%2F20+
c) +y=1%2F6x+ ; +1%2F6+
d) +y=1%2F18x+ ; +1%2F54+

1 solutions

Answer 221016 by ankor@dixie-net.com(15652) About Me  on 2010-05-27 13:19:05 (Show Source):
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Suppose that x and y vary inversely
let k = the constant of variation
y = 1%2F%28kx%29
:
and that y=1/6 when x=3.
1%2F6 = 1%2F%283k%29
Cross mult and find k
3k = 6
k = 6%2F3
k = 2
:
Write a function that models the inverse variation
y = 1%2F%282x%29
:
find y when x=10.
y = 1%2F%282%2810%29%29
y = 1%2F20


Rational-functions/308977: Suppose that y varies jointly with w and x and inversely with z and y=360 when w=8, x=25, and z=5. Write the equation that models the relationship. Then find y when w=4 and z=3.
1 solutions

Answer 221012 by ankor@dixie-net.com(15652) About Me  on 2010-05-27 12:57:51 (Show Source):
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Suppose that y varies jointly with w and x and inversely with z
Let k = the variation constant
y = %28k%2Aw%2Ax%29%2Fz
:
and y=360 when w=8, x=25, and z=5. Write the equation that models the relationship.
%28k%2A8%2A25%29%2F5 = 360
:
%28200k%29%2F5 = 360
:
40x = 360
k = 360%2F40
k = 9 is the constant
and
y = %289wx%29%2Fz is the equation
:
Then find y when w=4 and z=3. We have to know x, when you know that, use the above equation to find y


Equations/309012: I need to find all real or imaginary solutions to this equation.
Use the method of your choice.
√7x+29 = x + 3 note: sqrt extends over 7x+29

1 solutions

Answer 220964 by ankor@dixie-net.com(15652) About Me  on 2010-05-27 08:05:44 (Show Source):
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Use the method of your choice.
sqrt%287x%2B29%29 = x + 3
Square both sides
7x + 29 = (x + 3)^2
FOIL the right sides
7x + 29 = x^2 + 6x + 9
Combine like terms on the right
0 = x^2 + 6x - 7x + 9 - 29
A quadratic equation
x^2 - x - 20 = 0
Factors to
(x-5)(x+4) = 0
two solutions
x = +5
x = -4
;
check both solution in original equation
x = 5
sqrt%287%285%29%2B29%29 = 5 + 3
sqrt%2835%2B29%29 = 5 + 3
sqrt%2864%29 = 8
8 = 8, a good solution
:
x=-4
sqrt%287%28-4%29%2B29%29 = -4 + 3
sqrt%28-28%2B29%29 = -4 + 3
sqrt%281%29 = -1
+1 does not = -1, not a good solution