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Finance/303960: Use te clue to find the secret two-digit number. The sum of the digits is 9. The product of the digits is 18. The number is between 40 and 90.
What is the number?
1 solutions

Answer 217789 by ankor@dixie-net.com(15628) About Me  on 2010-05-12 21:34:41 (Show Source):
You can put this solution on YOUR website!
The sum of the digits is 9. The product of the digits is 18. The number is between 40 and 90.
What is the number?
:
Let 10x + y = the two digit number
:
"The sum of the digits is 9."
x + y = 9
y = (9-x)
:
The product of the digits is 18.
x * y = 18
Replace y with (9-x)
x(9-x) = 18
-x^2 + 9x = 18
-x^2 + 9x - 18 = 0
Multiply by -1 to change the signs
x^2 - 9x + 18 = 0
Factors easily to
(x-6)(x-3) = 0
x = 6, (no. is greater than 40)
then
y = 3
:
The number is between 40 and 90.
What is the number? It's 63


Exponential-and-logarithmic-functions/303996: Soil from beneath the Kish Church in Azerbaijan was found to have lost 12% of its carbon-14. How old was the soil?
1 solutions

Answer 217783 by ankor@dixie-net.com(15628) About Me  on 2010-05-12 21:24:07 (Show Source):
You can put this solution on YOUR website!
If soil was found to have lost 12% of it's carbon-14, then how old was the soil?
:
They should give you the half-life of Carbon 14. Most sources say it's 5730 yrs
:
The decay formula: A = Ao*2^(-t/h)
where
A = resulting amt after t yrs
Ao = initial amt (t=0)
t = time in yrs
h = half-life of substance (5730 yrs in this case)
:
Let Ao = 1, then remaining amt (A) after t yrs: 1 -.12 = .88 (lost 12%)
:
1*2^(-t/5730) = .88
using nat logs
ln[2^(-t/5730)] = ln(.88)
log equiv of exponents
-t%2F5730*ln(2) = ln(.88)
-t%2F5730*.693 = -.128
-t%2F5730 = %28-.128%29%2F.693
-t%2F5730 = -.1844
t = -5730 * -.1844
t = 1057 yrs old
;
:
Check solution on a calc: enter 2^(-1057/5730) = .8799 ~.88 or 88% remaining


Percentage-and-ratio-word-problems/303897: I'm having trouble figuring out the percentage of carbon-14. If soil was found to have lost 12% of it's carbon-14, then how old was the soil?
1 solutions

Answer 217780 by ankor@dixie-net.com(15628) About Me  on 2010-05-12 21:21:20 (Show Source):
You can put this solution on YOUR website!
percentage of carbon-14.
If soil was found to have lost 12% of it's carbon-14, then how old was the soil?
:
They should give you the half-life of Carbon 14. Most sources say it's 5730 yrs
:
The decay formula: A = Ao*2^(-t/h)
where
A = resulting amt after t yrs
Ao = initial amt (t=0)
t = time in yrs
h = half-life of substance (5730 yrs in this case)
:
Let Ao = 1, then remaining amt (A) after t yrs: 1 -.12 = .88 (lost 12%)
:
1*2^(-t/5730) = .88
using nat logs
ln[2^(-t/5730)] = ln(.88)
log equiv of exponents
-t%2F5730*ln(2) = ln(.88)
-t%2F5730*.693 = -.128
-t%2F5730 = %28-.128%29%2F.693
-t%2F5730 = -.1844
t = -5730 * -.1844
t = 1057 yrs old
;
:
Check solution on a calc: enter 2^(-1057/5730) = .8799 ~.88 or 88% remaining


Rectangles/303652: the width of a rectangle is 5 inches shorter than the length and that the perimeter or the rectangle is 50 inches. set up and equation for the perimeter involving the length. solve this equation algebraically to find the length and width.
Thank-you
Shirley Sims
shirleysims174@aol.com
1 solutions

Answer 217644 by ankor@dixie-net.com(15628) About Me  on 2010-05-12 14:17:03 (Show Source):
You can put this solution on YOUR website!
the width of a rectangle is 5 inches shorter than the length and that the
W = L - 5
:
perimeter or the rectangle is 50 inches.
2L + 2W = 50
:
set up an equation for the perimeter involving the length.
Replace W with (L-5)
2L + 2(L-5) = 50
solve this equation algebraically to find the length and width.
2L + 2L - 10 = 50
4L = 50 + 10
4L = 60
L = 60%2F4
L = 15 in is the lenght
then
W = L - 5
W = 15 - 5
W = 10 in is the width
:
:
Check solution by finding the perimeter with these values for L & W
2(15) + 2(10) = 50



Quadratic_Equations/303705: What quadratic equation would have solutions x= 2/3 and x=1/5
1 solutions

Answer 217619 by ankor@dixie-net.com(15628) About Me  on 2010-05-12 12:26:37 (Show Source):
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What quadratic equation would have solutions x= 2/3 and x=1/5
x = 2/3; from the factor: (3x - 2)
and
x = 1/5; from the factor: (5x - 1)
:
FOIL
(3x - 2)(5x-1) = 15x^2 - 3x - 10x + 2 = (15x^2 - 13x + 2) is the equation


Linear-equations/303515: find the slope of 15x = 5y + 2
1 solutions

Answer 217526 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 21:59:17 (Show Source):
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find the slope of
15x = 5y + 2
Subtract 15x from both sides
0 = -15x + 5y + 2
subtract 5y from both sides
-5y = -15x + 2
Multiply both sides by -1
5y = 15x - 2
divide both sides by 5
y = 3x - 2%2F5
or
y = 3x - .4
:
This this is the slope intercept form y - mx - b
slope (m) = +3


Linear_Equations_And_Systems_Word_Problems/303374: the hundreds digits is two times the ones digits. the ones digits is two times the tens digit. All the digits are even numbers what is the number?
sweetmako@ymail.com
1 solutions

Answer 217523 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 21:45:29 (Show Source):
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Let x = the 100's digit
Let y = the 10's digit
Let z = the ones digit
:
100x + 10y + z = the number
:
Write an equation for each statement:
"the hundreds digits is two times the ones digits."
x = 2z
:
"the ones digits is two times the tens digit."
z = 2y
:
replace z with 2y in the 1st equation
x = 2(2y)
x = 4y
All the digits are even numbers
from this we know y has to = 2 then x = 8
:
thn z = 2(2) = 4:
:
The number 824


Percentage-and-ratio-word-problems/303492: Im thinking of an integer. Half of this integer is more than one third of the next integer. What is this integer?
1 solutions

Answer 217516 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 21:29:44 (Show Source):
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Im thinking of an integer.
Half of this integer is more than one third of the next integer.
What is this integer?
:
x = "the integer"
:
1%2F2x > 1%2F3(x+1)
multiply by 6, results
3x > 2(x+1)
3x > 2x + 2
3x - 2x > 2
x > 2
:
See if that is true, assume x=3
1%2F2(3) > 1%2F3(4)
1.5 > 1.33


Polynomials-and-rational-expressions/303313: Please Help, I am confused about how to work with third roots.
I am supposed to multiply then simplify by factoring.
(3rd root)of y^7 * (3rd root) of 16y^8
Use Rational exponents to simplify the third root of x^6
Find the 16th root of (-8)^16
Rewrite the 4th root of 23 with a rational exponent.
Simplify the 3rd root of -1/64
Simplify by taking roots of the numerator and denominator
(3rd root) of 1000x^14/y^3
Solve
The square root of 5x+29 = x+3
I am completely lost when working with roots. Any help would be greatly appreciated!
1 solutions

Answer 217510 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 21:07:05 (Show Source):
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multiply then simplify by factoring.
Use this as a cube root 3sqrt%28n%29 symbol
:
(3rd root)of y^7 * (3rd root) of 16y^8
3sqrt%28y%5E7%29+%2A+3sqrt%2816y%5E8%29
:
We can combine these under single radical
3sqrt%2816y%5E8y%5E7%29
:
Add exponents when you multiply
3sqrt%2816y%5E15%29
:
Factor to reveal perfect cubes
3sqrt%288%2A2%2Ay%5E3%2Ay%5E3%2Ay%5E3%2Ay%5E3%2Ay%5E3%29
:
Extract those perfect cubes
2%2Ay%5E5%2A3sqrt%282%29
:
:
Use Rational exponents to simplify the third root of x^6
to raise on power to another power, multiply exponents
%28x%5E6%29%5E%281%2F3%29 = x%5E%286%2A%281%2F3%29%29 = x%5E2
:
:
Find the 16th root of (-8)^16
%28%28-8%29%5E16%29%5E%281%2F16%29 = %28-8%29%5E%2816%2A%281%2F16%29%29 = %28-8%29%5E1 = -8
:
:
Rewrite the 4th root of 23 with a rational exponent.
23%5E%281%2F4%29
:
:
Simplify the 3rd root of -1/64
3sqrt%28-1%2F64%29 = 3sqrt%28%28-1%2F4%29%2A%28-1%2F4%29%2A%28-1%2F4%29%29 = %28-1%2F4%29
:
:
Simplify by taking roots of the numerator and denominator
(3rd root) of 1000x^14/y^3
3sqrt%281000x%5E14%2Fy%5E3%29
Extract cube root 1/y^3
%281%2Fy%29%2A3sqrt%281000x%5E14%29
Extract the cube root of 1000
%2810%2Fy%29%2A3sqrt%28x%5E14%29
Factor inside the radical
%2810%2Fy%29%2A3sqrt%28x%5E3%2Ax%5E3%2Ax%5E3%2Ax%5E3%2Ax%5E2%29
Extract
%2810%2Fy%29%2Ax%5E4%2A3sqrt%28x%5E2%29
:
;
Solve
The square root of 5x+29 = x+3
sqrt%285x%2B29%29+=+x%2B3
square both sides:
5x + 29 = (x+3)^2
FOIL the right side
5x + 29 = x^2 + 6x + 9
combine like terms on the right
0 = x^2 + 6x - 5x + 9 - 29
A quadratic equation
x^2 + x - 20 = 0
Factors to
(x+5)(x-4) = 0
two solutions
x = -5
and
x = +4
:
Check both solution in original equation
x = -5
sqrt%285%29-5%29%2B29%29+=+-5%2B3
sqrt%28-25%2B29%29+=+-2
sqrt%284%29+=+-2 not a solution
x = 4
sqrt%285%284%29%2B29%29+=+4%2B3
sqrt%2820%2B29%29+=+7
sqrt%2849%29+=+7; a good solution (x=4)


Travel_Word_Problems/303296: A family makes a 43.25 km trip in 5.5 hours. On the first part of the trip they crossed a lake in a canoe paddling at 12 km/h. For the rest of the trip, they hiked on a scenic trail. If their average walking speed was 5 km/h, how far did they walk?
1 solutions

Answer 217448 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 19:00:11 (Show Source):
You can put this solution on YOUR website!
A family makes a 43.25 km trip in 5.5 hours.
On the first part of the trip they crossed a lake in a canoe paddling at 12 km/h.
For the rest of the trip, they hiked on a scenic trail.
If their average walking speed was 5 km/h, how far did they walk?
:
let x = distance walked
then
(43.25-x) = distance paddled
:
Write a time equation: time = dist/speed
:
walk time + paddle time = 5.5 hrs
x%2F5 + %2843.25-x%29%2F12 = 5.5
Multiply by 60 to clear the denominators, results
12x + 5(43.25-x) = 60(5.5)
:
12x + 216.25 - 5x = 330
:
12x - 5x = 330 - 216.25
:
7x = 113.75
x = 113.75%2F7
x = 16.25 km walked
then
43.25 - 16.25 = 27 km paddled
:
:
Check solutions by finding the total time
16.25/5 =3.25 hrs
27/12 = 2.25 hrs
------------------
total hrs:5.5 hrs, confirms our solutions of x = 16.25 km walked


Percentage-and-ratio-word-problems/303126: To make a shade of orange paint that you like, you must mix 2/3 of a bottle of red paint with each 4/5 of a bottle of yellow paint that you use. You need 88 bottles of this orange paint. How many bottles of red paint will you need and how many bottles of yellow paint will you need? (All bottles are the same size.)
1 solutions

Answer 217436 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 17:02:18 (Show Source):
You can put this solution on YOUR website!
o make a shade of orange paint that you like, you must mix 2/3 of a bottle of
red paint with each 4/5 of a bottle of yellow paint that you use.
You need 88 bottles of this orange paint.
How many bottles of red paint will you need and how many bottles of yellow paint will you need? (All bottles are the same size.)
:
Ratio of red:yellow to make orange
%282%2F3%29%2F%284%2F5%29 = 2%2F3 * 5%2F4 = 10%2F12 = 5%2F6
:
r:y = 5:6
then we know:
r + y = 11
therefore
5%2F11*88 = 40 bottles of red
and
6%2F11*88 = 48 bottles of yellow
:


Linear-systems/303263: Please help me to solve this equation:
x+y+z=2
-x+2y+3z=2
2x-3y-z=1
x-y-z=0
1 solutions

Answer 217382 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 16:06:48 (Show Source):
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solve this equation:
x + y + z = 2
-x+2y +3z = 2
2x-3y -z = 1
x - y -z = 0
:
Using the 1st and 4th equation
x + y + z = 2
x - y - z = 0
---------------------Addition eliminates y and z, find x
2x = 2
x = 1
:
Use the 2nd and 3rd equation, replace x with 1
-1+2y +3z = 2
2 -3y -z = 1
:
+2y +3z = 2 + 1
3y - z = 1 - 2
:
+2y +3z = 3
3y - z = -1
:
Multiply the above equation by 3, and add to 2y + 3z = 3
9y - 3z = -3
2y + 3z = 3
----------------- addition eliminates z, find y
11y = 0
y = 0
:
Find z using: x + y + z = 2
1 + 0 + z = 2
z = 2 -1
z = 1
:
Summarize x=1, y=0, z=1
:
Check solution in the 2nd equation: -x+2y +3z = 2
-1 + 2(0) + 3(1) =
-1 + 3 = 2


Miscellaneous_Word_Problems/303234: Walking beside you, your friend takes 50 strides per minute while you take 48 strides per minute. If you start in step, when will you be in step again?
1 solutions

Answer 217351 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 15:13:59 (Show Source):
You can put this solution on YOUR website!
Walking beside you, your friend takes 50 strides per minute while you take 48 strides per minute.
If you start in step, when will you be in step again?
:
Let m = no. of minutes to be in step
50(m-1) = 48m
50m - 50 = 48m
50m - 48m = 50
2m = 50
m = 25 minutes
:
therefore in 25 min you will be in step because:
your friend has completed 25*50 = 1250 steps
while you have completed 25*48 = 1200 steps


Pythagorean-theorem/303246: your boat is traveling due north at 20 miles per hour. a friend's boat left at the same time and is traveling due west at 15 miles per hour. after an hour you get a call from your friend who tells you that he has just stopped because of engine trouble. how far must you travel to reach your friend?
1 solutions

Answer 217338 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 14:29:27 (Show Source):
You can put this solution on YOUR website!
boat is traveling due north at 20 miles per hour.
a friend's boat left at the same time and is traveling due west at 15 miles per hour.
after an hour you get a call from your friend who tells you that he has just
stopped because of engine trouble. how far must you travel
:
this a right triangle problem, the distance between the boat is the hypotenuse
c^2 = a^2 + b^2
where
a = 20
b = 15
c = distance between the boats
:
c^2 = 20^2 + 15^2
c^2 = 400 + 225
c^2 = 625
c = sqrt%28625%29
c = 25 miles to travel to the friend


Complex_Numbers/303258: Simplify if possible.
4a+10/a-1 Devide 3a+7/a-1
1 solutions

Answer 217334 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 14:12:40 (Show Source):
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Simplify if possible.
%284a%2B10%29%2F%28a-1%29
------------------
%283a%2B7%29%2F%28a-1%29
:
Invert the dividing fraction and multiply
%284a%2B10%29%2F%28a-1%29 * %28a-1%29%2F%283a%2B7%29
Cancel (a-1)'s
%284a%2B10%29%2A%281%2F%283a%2B7%29%29 = %284a%2B10%29%2F%283a%2B7%29


Miscellaneous_Word_Problems/303077: Quinn can refinish hardwood floors four times as fast as Jack. They have to refinish 100 ft^2 of flooring. Working together, Quinn and Jack can finish the job in 3 hours. How long would it take each of them working alone?
1 solutions

Answer 217332 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 14:05:14 (Show Source):
You can put this solution on YOUR website!
Quinn can refinish hardwood floors four times as fast as Jack.
They have to refinish 100 ft^2 of flooring.
Working together, Quinn and Jack can finish the job in 3 hours.
How long would it take each of them working alone?
:
Let t = time required by Q to complete job alone
then
4t = time required by J
:
Let the completed job (refinishing 100sq/ft) = 1
:
3%2Ft + 3%2F%284t%29 = 1
multiply each term by 4t, results
4(3) + 3 = 4t
12 + 3 = 4t
15 = 4t
t = 15%2F4
t = 3.75 hrs, Q alone
then
4(3.75) = 15 hrs, J alone
:
:
Check this:
3/3.75 + 3/15 =
.8 + .2 = 1


Polynomials-and-rational-expressions/303005: Hi My name is Nick and I was having probloms with the question as follows:
Find The Product of the Square of the Binomial.
(10r-1) Squared.
1 solutions

Answer 217307 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 12:17:42 (Show Source):
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Find The Product of the Square of the Binomial.
(10r - 1)^2
:
FOIL
(10r - 1)(10r - 1) = 100r^2 - 10r - 10r + 1 = 100r^2 - 20r + 1; is the product


Age_Word_Problems/303143: Jack is twice as old as Jill but in five years time he will only be one and half times as old. How old is Jack and Jill now?
1 solutions

Answer 217245 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 08:44:38 (Show Source):
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Jack is twice as old as Jill
Ja = 2Ji
:
but in five years time he will only be one and half times as old.
Ja + 5 = 1.5(Ji+5)
Ja + 5 = 1.5Ji + 7.5
Ja = 1.5Ji + 7.5 - 5
Ja = 1.5Ji + 2.5
Replace Ja with 2Ji
2Ji = 1.5Ji + 2.5
2Ji - 1.5Ji = 2.5
.5Ji = 2.5
Mult both sides by 2
Ji = 5
:
I'll let you find Ja's age




Square-cubic-other-roots/303139: the square root of 200x^3y/ the square root of 2xy^5
1 solutions

Answer 217244 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 08:38:14 (Show Source):
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the square root of 200x^3y/ the square root of 2xy^5
%28200x%5E3y%29%2F%282xy%5E5%29
Cancel 2 into 200
%28100x%5E3y%29%2F%28xy%5E5%29
combine like terms, in a manner to avoid neg exponents
%28100x%5E%283-1%29%29%2F%28y%5E%285-1%29%29 = %28100x%5E2%29%2F%28y%5E4%29


Divisibility_and_Prime_Numbers/303133: The tens digit of a two-digit number is 3 and the units digit is H. if the two-digit number is divisible by H, which of the following cannot be the value of H ?
A 2 b 3 c 4 d 5 e 6

1 solutions

Answer 217242 by ankor@dixie-net.com(15628) About Me  on 2010-05-11 08:02:58 (Show Source):
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The tens digit of a two-digit number is 3 and the units digit is H.
if the two-digit number is divisible by H, which of the following cannot be the value of H ?
4, 34 is not divisible by 4


Radicals/302920: How do you perform the necessary steps to isolate the radical on the right-hand side of the equation?
3x - 6 = 2x + 2y + 1 - 9
2y + 1 is under a radical

Thank you!

1 solutions

Answer 217205 by ankor@dixie-net.com(15628) About Me  on 2010-05-10 21:57:19 (Show Source):
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Assume the problem is
3x+-+6+=+2x+%2B+sqrt%282y+%2B+1%29+-+9+
subtract 2x and add 9 to both sides and you hve
3x+-+2x+-+6+%2B+9+=++sqrt%282y+%2B+1%29
:
x+%2B+3+=+sqrt%282y+%2B+1%29
:


Linear-equations/302916: Here is more of the same, an accuplacer practice. 3/10x plus 9/14x^2
ie 3 over 10x plus 9 over 14x squared = ? The correct answer is 3(7x+15) over 70x squared. How to get there, I don't know. With apologies beforehand to London Maths Tutor and others, I should point out that I'm kind of dense. So if anybody tackling this one could include and explain steps in the process even if they seem blindingly obvious, that would be super! Thanks much, Mike
1 solutions

Answer 217202 by ankor@dixie-net.com(15628) About Me  on 2010-05-10 21:49:01 (Show Source):
You can put this solution on YOUR website!
3/10x plus 9/14x^2
Assume the problem is:
3%2F%2810x%29 + 9%2F%2814x%5E2%29
looking at the denominator you can see the common denominator will be 70x^2
:
Divide the denominator into the common denominator and multiply the numerator by that value.
%287x%283%29+%2B+5%289%29%29%2F%2870x%5E2%29 = %2821x+%2B+45%29%2F%2870x%5E2%29
Factor out 3 in the numerator
%283%287x+%2B+15%29%29%2F%2870x%5E2%29
:
Did that make sense, Mike?


Sequences-and-series/302992: The mean of five numbers is 6. If one of the five numbers is removed, the mean becomes 7. What is the value of the number that was removed?
1 solutions

Answer 217192 by ankor@dixie-net.com(15628) About Me  on 2010-05-10 21:30:41 (Show Source):
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The mean of five numbers is 6.
If one of the five numbers is removed, the mean becomes 7.
What is the value of the number that was removed?
:
Let x = value of the 1st 4 numbers
Let y = value of the number to be removed
:
%28x+%2B+y%29%2F5 = 6
x + y = 5(6)
x + y = 30
then "one of the five numbers is removed, the mean becomes 7.
x%2F4 = 7
x = 4(7)
x = 28
:
Substitute 28 for x in the equation: x + y = 30
28 + y = 30
y = 20 - 28
y = 2, is the value of the number removed


Rectangles/302721: A hawk can fly 300 miles in 8 hours with the wind. Flying against the wind, the hawk covers only one-third of the distance in 7 hours. What is the rate of the wind?
1 solutions

Answer 217189 by ankor@dixie-net.com(15628) About Me  on 2010-05-10 21:17:56 (Show Source):
You can put this solution on YOUR website!
A hawk can fly 300 miles in 8 hours with the wind.
Flying against the wind, the hawk covers only one-third of the distance in 7 hours.
What is the rate of the wind?
;
let w = the rate of the wind
let s = the flying rate of the hawk
then
(s+w) = effective speed with the wind
(s-w) = effective speed against the wind
:
Two distance equations:
8(s+w) = 300
7(s-w) = 100
:
8s + 8w = 300
7s - 7w = 100
:
Multiply the 1st equation by 7 & the 2nd equation by 8, subtract
56s + 56w = 2100
56s - 56w = 800
-------------------subtraction eliminates s, find w
112w = 1300
w = 1300%2F112
w = 11.6 mph is the rate of the wind
:
:
Find the speed of the hawk to check our solution for the wind
8s + 8(11.6) = 300
8s = 92.8 = 300
8s = 300 - 92.8
s = 207.2%2F8
s = 25.9 mph
:
Check it in the 2nd equation
7s - 7w = 100
7(25.9) - 7(11.6) =
181.3 - 81.2 = 100.1 ~ 100; confirms our solution for wind = 11.6 mph


Expressions-with-variables/302548: It takes a small jet plane 4 hours less time than it takes a propeller driven plane to travel from Glen Rock to Oakville. The jet plane averages 637 km/h while the propeller plane averages 273 km/h. How far is it from Glen Rock to Oakville?
1 solutions

Answer 217161 by ankor@dixie-net.com(15628) About Me  on 2010-05-10 19:20:13 (Show Source):
You can put this solution on YOUR website!
It takes a small jet plane 4 hours less time than it takes a propeller driven
plane to travel from Glen Rock to Oakville.
The jet plane averages 637 km/h while the propeller plane averages 273 km/h.
How far is it from Glen Rock to Oakville?
:
Let d = distance between these two towns
:
Write a time equation, Time = dist/speed
:
Prop time = Jet time + 4 hrs
d%2F273 = d%2F637 + 4
Multiply by 173901(273*637) to clear the denominators, results:
637d = 273d + 4(173901)
:
637d - 273d = 695604
:
364d = 695604
d = 695604%2F364
d = 1911 km between these two downs
;
:
Check solution by finding the times of each
1911/273 = 7 hrs
1911/637 = 3 hrs
-------------------
difference 4 hrs


Polynomials-and-rational-expressions/302714: x^5-11^4+30x^3
x^5-11x+30....I don't know if I'm on the right track, but any help is appreciated so much I believe this needs to be factored completly.
Thank you!!!
1 solutions

Answer 217155 by ankor@dixie-net.com(15628) About Me  on 2010-05-10 19:02:05 (Show Source):
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x^5 - 11^4 + 30x^3
Factor out x^3
x^3(x^2 - 11x + 30)
Factor further
x^3(x-5)(x-6)


logarithm/302792: 1a. What system of equations could you enter on your graphing calculator to solve the exponential equations 6^(x-1)=7
1b. Use your system of equations and your graphing calculator to solve the exponential equation given in question 1.a. Round your answer to 3 decimal places. Sketch your calculator display that gives your answer.

Please and thank you in advance
1 solutions

Answer 217067 by ankor@dixie-net.com(15628) About Me  on 2010-05-10 15:48:41 (Show Source):
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1a. What system of equations could you enter on your graphing calculator
to solve the exponential equations 6^(x-1)= 7
Subtract 7 from both sides
6^(x-1) - 7 = 0
y = 6^(x-1) - 7
:
1b. Use your system of equations and your graphing calculator to solve the
exponential equation given in question 1.
Enter into y=: 6^(x-1)-7
Select: calc 2:Zero feature, x = 2.086
:
a. Round your answer to 3 decimal places. Sketch your calculator display that gives your answer.
:
+graph%28+300%2C+200%2C+-3%2C+5%2C+-10%2C+10%2C+6%5E%28x-1%29-7%29+


Length-and-distance/302671:
There is an equilateral triangle where each side is 2x-7, x+y-9 and y+5
Calculate the value of x and find the length of the sides of the triangle
1 solutions

Answer 217044 by ankor@dixie-net.com(15628) About Me  on 2010-05-10 15:15:23 (Show Source):
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There is an equilateral triangle where each side is 2x-7, x+y-9 and y+5
:
All side equal, therefore
2x - 7 = x + y - 9
2x - x - y = -9 + 7
x - y = -2
and
2x - 7 = y + 5
2x - y = 5 + 7
2x - y = 12
Subtract the 1st equation from the above equation
2x - y = 12
x - y = -2
---------------subtraction eliminates y
x = 14
find y
x - y = -2
14 - y = -2
-y = -2 -14
-y = -16
y = 16
:
Find the 3 sides, a, b, c
a = 2x-7
a = 2(14) - 7
a = 28 - 7
a = 21
:
b = x + y - 9
b = 14 + 16 - 9
b = 21
:
c = y + 5
c = 16 + 5
c = 21


Rate-of-work-word-problems/302709: an inlet on a pool can be used to fill a pool in 34 hours. the drain pipe can be used to empty to empty a pool in 36 hours. If a pool was 1/3 full and the inlet and outlet are opened, how long will it take to fill the pool?
1 solutions

Answer 217029 by ankor@dixie-net.com(15628) About Me  on 2010-05-10 13:50:53 (Show Source):
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an inlet on a pool can be used to fill a pool in 34 hours.
the drain pipe can be used to empty to empty a pool in 36 hours.
If a pool was 1/3 full and the inlet and outlet are opened, how long will it take to fill the pool?
:
Let t = time required to fill the pool under these conditions
:
Let the full pool = 1
:
The equation to fill the remaining 2/3 of the pool
:
t%2F34 - t%2F36 = 2%2F3
multiply by 1224 (36*34) to clear the denominators
36t - 34t = 408(2)
2t = 816
t = 408 hrs to fill the pool


Rectangles/302686: I have presented this problem in the past and have not gotten a clear understanding of what is the correct formula and steps to take to get the correct answer. Please Help!!!
Ther perimeter of a rectangle is 20 meters. If the length is increased by four times the width, the sum is 19 meters. What are the dimensions of the rectangle? What is its area?
1 solutions

Answer 217019 by ankor@dixie-net.com(15628) About Me  on 2010-05-10 13:26:53 (Show Source):
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The perimeter of a rectangle is 20 meters.
If the length is increased by four times the width, the sum is 19 meters.
What are the dimensions of the rectangle? What is its area?
:
Let L = the length of the rectangle
Let W = the width
:
Write an equation for each statement
"The perimeter of a rectangle is 20 meters."
2L + 2W = 20
We can simplify this divide by 2, results:
L + W = 10
W = (10-L); this form for substitution
:
"the length is increased by four times the width, the sum is 19 meters."
L + 4W = 19
Substitute W with (10-L)
L + 4(10-L) = 19
L + 40 - 4L = 19
L - 4L = 19 - 40
-3L = - 21
L = %28-21%29%2F%28-3%29
L = +7m is the length
:
What are the dimensions of the rectangle?
find the width
W = 10 - L
W = 10 - 7
W = 3m
:
Dimensions: 7 by 3
:
What is its area? 7 * 3 = 21 sq/m
:
:
Check solutions by finding the perimeter with these dimensions
2(7) + 2(3) = 20


Polynomials-and-rational-expressions/302370: an athlete whose event is the shot put releases a shot. when the shot is released at an angle of 35 degree, its height, f(x), in feet, can be modeled by f(x)=-0.01x2+0.7x+5.3, where x is the shot's horizontal ditance, in feet, from its point of release.
a. what is the maximum height of the shot and how far from its point of release does this occur?
the maximum height is ____, which occurs ____feet from the point of release.
1 solutions

Answer 216975 by ankor@dixie-net.com(15628) About Me  on 2010-05-10 08:16:07 (Show Source):
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an athlete whose event is the shot put releases a shot.
when the shot is released at an angle of 35 degree, its height, f(x), in feet,
can be modeled by f(x)=-0.01x2+0.7x+5.3, where x is the shot's horizontal
distance, in feet, from its point of release.
:
a. what is the maximum height of the shot and how far from its point of release does this occur?
the maximum height is ____, which occurs ____feet from the point of release.
:
f(x)=-0.01x^2 +0.7x + 5.3
Find the axis of symmetry using the formula: x = -b/(2a)
where: a=-.01, b=.7
:
x = %28-.7%29%2F%282%2A-.01%29
x = %28-.7%29%2F%28-.02%29
x = 35 ft, the horizontal dist to find max height
:
Find the height, replace x with 35 in the original equation
h = =-0.01(35^2) +0.7(35) + 5.3
h = -.01*1225 + 24.5 + 5.3
h = -12.25 + 24.5 + 5.3
h = 17.55 ft is the max height