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Travel_Word_Problems/469487: how long would it take to get 10 miles going 175 miles per hour
1 solutions

Answer 322122 by nerdybill(6948) About Me  on 2011-07-12 09:41:02 (Show Source):
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how long would it take to get 10 miles going 175 miles per hour
applying the "distance formula":
d = rt
10 = 175t
10/175 = t
0.0571 hours = t
or
3.43 minutes = t


Miscellaneous_Word_Problems/469478: a pipe can fill a pool in 8 hours another pipe fill in 12 hours. if both pipes are applied to fill pool than how many hours it will take???
1 solutions

Answer 322119 by nerdybill(6948) About Me  on 2011-07-12 09:39:25 (Show Source):
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a pipe can fill a pool in 8 hours another pipe fill in 12 hours. if both pipes are applied to fill pool than how many hours it will take???
.
Let x = time (hrs) it takes for both
then
x(1/8 + 1/12)= 1
multiplying both sides by 96:
x(12 + 8)= 96
x(20)= 96
x = 4.8 hours
or
x = 4 hours and 48 minutes


Rate-of-work-word-problems/469308: can someone help me plssssssssss :)?
it takes carolyn 4 hr to type a final exam. it takes Elise 3 hr to do the same job. How long would it take them, working together, to do the typing?
1 solutions

Answer 321958 by nerdybill(6948) About Me  on 2011-07-11 17:40:48 (Show Source):
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it takes carolyn 4 hr to type a final exam. it takes Elise 3 hr to do the same job. How long would it take them, working together, to do the typing?
.
Let x = time (hours) it takes for both
then
x(1/4 + 1/3) = 1
multiplying both sides by 12:
x(3 + 4) = 12
x(7) = 12
x = 12/7
x = 1.7 hours
or
x = 1 hour and 43 minutes


Length-and-distance/469155: What Is The Slope Of A Line parallel to y = -2/5x + 4/5
1 solutions

Answer 321895 by nerdybill(6948) About Me  on 2011-07-11 08:56:38 (Show Source):
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What Is The Slope Of A Line parallel to y = -2/5x + 4/5
.
Two lines are parallel if it has the same slope.
because
y = -2/5x + 4/5
is in "slope-intercept" form:
y = mx + b
we see that the slope is -2/5
.
Answer: -2/5


logarithm/468854: 2 log 1

1 solutions

Answer 321672 by nerdybill(6948) About Me  on 2011-07-10 10:10:45 (Show Source):
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2 log 1
Since log(1) = 0
we have
2*0
so, the whole thing is equal to
0


Quadratic_Equations/468702: Solve.
9x^4-18x^2+5=0
Would someone please help me solve this problem. I come up with various answers, and I know that there is only one set of answers. Thank you very much.
1 solutions

Answer 321579 by nerdybill(6948) About Me  on 2011-07-09 18:05:48 (Show Source):
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9x^4-18x^2+5=0
rewrite as:
9x^4-15x^2-3x^2+5=0
group terms:
(9x^4-15x^2)-(3x^2-5)=0
3x^2(3x^2-5)-(3x^2-5)=0
(3x^2-5)(3x^2-1)=0
.
x = {sqrt(5/3), sqrt(1/3)}
rationalize denominators:
x = { sqrt%2815%29%2F3%29, sqrt%283%29%2F3 }


Exponential-and-logarithmic-functions/468582: Solve the problem.
An-Mei owns a business making and selling jackets. She has a fixed cost of $1190. It costs $92 to produce each jacket. The selling price is $109 per jacket. Let x represent the number of jackets produced and sold and write the cost function, C, and revenue function, R.

1 solutions

Answer 321529 by nerdybill(6948) About Me  on 2011-07-09 11:37:37 (Show Source):
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An-Mei owns a business making and selling jackets. She has a fixed cost of $1190. It costs $92 to produce each jacket. The selling price is $109 per jacket. Let x represent the number of jackets produced and sold and write the cost function, C, and revenue function, R.
.
Cost Function:
C(x) = 92x + 1190
.
Revenue function:
R(x) = 109x - (92x + 1190)
R(x) = 17x - 1190


test/468580: Use the given conditions to write an equation for the lone in point-slope form slope=6/7, passing through (7,3)
1 solutions

Answer 321528 by nerdybill(6948) About Me  on 2011-07-09 11:30:39 (Show Source):
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Use the given conditions to write an equation for the lone in point-slope form slope=6/7, passing through (7,3)
.
"Point-slope" form is:
y - y1 = m(x - x1)
plugging in the given information:
y - 3 = (6/7)(x - 7)


Exponential-and-logarithmic-functions/468592: Use properties of logarithms to expand the logarithmic expression as much as possible.
logb (yz5)

1 solutions

Answer 321525 by nerdybill(6948) About Me  on 2011-07-09 11:28:00 (Show Source):


Exponential-and-logarithmic-functions/468590: Use properties of logarithms to condense the logarithmic expression.
ln x + 8ln y

1 solutions

Answer 321524 by nerdybill(6948) About Me  on 2011-07-09 11:26:12 (Show Source):
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ln(x) + 8ln(y)
ln(x) + ln(y^8)
ln(xy^8)


Functions/468386: y = -6x + 2
is y a function of x?
1 solutions

Answer 321400 by nerdybill(6948) About Me  on 2011-07-08 17:25:18 (Show Source):


test/468412: If 3a + 4b=b which of the following must equal 6a + 6b?
(a). 0
(b). 12
(c) 12b
1 solutions

Answer 321398 by nerdybill(6948) About Me  on 2011-07-08 17:24:28 (Show Source):
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3a + 4b=b
subtracting b from both sides:
3a + 3b=0
multiplying both sides by 2:
6a + 6b=0
.
Answer: 'a'


Graphs/468407: Write the slope intercept equation for the line that passes through (-9,-5) and has a slope of 2/9.
1 solutions

Answer 321394 by nerdybill(6948) About Me  on 2011-07-08 17:14:29 (Show Source):
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Write the slope intercept equation for the line that passes through (-9,-5) and has a slope of 2/9.
.
use "point-slope" form:
y - y1 = m(x - x1)
y - (-5) = (2/9)(x - (-9))
y + 5 = (2/9)(x + 9)
y + 5 = (2/9)x + 2
y = (2/9)x + 2 - 5
y = (2/9)x - 3



logarithm/468369: ln(2x-3)=4
round to nearest thousandth
1 solutions

Answer 321384 by nerdybill(6948) About Me  on 2011-07-08 15:47:48 (Show Source):
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ln(2x-3)=4
2x-3=e^4
2x=e^4 + 3
x = (e^4 + 3)/2
x = 28.799


test/468387: Please help me find the domain of this function x%5E4%2F%28x%5E2%2Bx-6%29
1 solutions

Answer 321383 by nerdybill(6948) About Me  on 2011-07-08 15:45:59 (Show Source):
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The domain specifies all values that makes sense for 'x'.
You only have to eliminate numbers that drives the denominator to zero.
x^2+x-6 = 0
(x-3)(x+2) = 0
x = {-2,3} (these are the numbers that must be eliminated)
.
thus the domain (in interval notation) is
(-oo, -2) U (-2,3) U (3, +oo)
where
oo is infinity


test/468231: A builder is building a rectangular deck with dimensions of 16 feet by 30 feet. To ensure that the sides form 90 degree angles, what should each diagonal measure? (A). 30ft. (B). 34ft. (C). 46ft. (D). 16ft
1 solutions

Answer 321311 by nerdybill(6948) About Me  on 2011-07-08 10:32:20 (Show Source):
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apply Pythagorean theorem
Let d = diagonal
then
d^2 = 16^2 + 30^2
d^2 = 256 + 900
d^2 = 1156
d = 34 feet



Angles/468255: the supplement of an angle is 6 times its complement. Find an angle ?

1 solutions

Answer 321289 by nerdybill(6948) About Me  on 2011-07-08 08:50:43 (Show Source):
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the supplement of an angle is 6 times its complement. Find an angle ?
.
Let x = the angle
then
90-x = the complement
180-x = the supplement
.
180-x = 6(90-x)
180-x = 540-6x
180+5x = 540
5x = 360
x = 72 degrees


Coordinate-system/468070: Is there a difference between no slope and an undefined slope of a straight line? If so,then what is it?
1 solutions

Answer 321144 by nerdybill(6948) About Me  on 2011-07-07 14:17:43 (Show Source):
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"no slope" describes a horizontal line
whereaas
"undefined slope" describes a vertical line


Problems-with-consecutive-odd-even-integers/467653: I am thinking of two consecutive even integers. The sum of their squares is 340. what are the integers? PLEASE HELP!
1 solutions

Answer 320886 by nerdybill(6948) About Me  on 2011-07-06 14:14:42 (Show Source):
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I am thinking of two consecutive even integers. The sum of their squares is 340. what are the integers?
.
Let x = first of two consecutive even integers
then
x+2 = second even integer
.
x^2 + (x+2)^2 = 340
x^2 + (x+2)(x+2) = 340
x^2 + x^2+4x+4 = 340
2x^2+4x+4 = 340
x^2+2x+2 = 170
x^2+2x-168 = 0
(x+14)(x-12) = 0
x = {-14, 12}
.
solution:
the two integers are
12 and 14
or
-12 and -14


Polynomials-and-rational-expressions/467658: is y²−5y-24 factorable?
1 solutions

Answer 320884 by nerdybill(6948) About Me  on 2011-07-06 14:11:00 (Show Source):
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Yes.
(y-8)(y+3)


Miscellaneous_Word_Problems/467569: A 2005 Honda minivan can travel 240 miles in the city on 4 gallons of gas. Find the amount of gas required for 360 miles of city driving. (hint: use a proportion).
1 solutions

Answer 320861 by nerdybill(6948) About Me  on 2011-07-06 12:40:06 (Show Source):
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A 2005 Honda minivan can travel 240 miles in the city on 4 gallons of gas. Find the amount of gas required for 360 miles of city driving. (hint: use a proportion).
.
Let x = amt of gas (gallons) used to drive 360 miles
then
240/4 = 360/x
cross multiplying:
240x = 4(360)
240x = 1440
x = 6 gallons



Angles/467561: An angle is equal to eight times its complement. Determine its measure.
Let x be the angle
then
90-x is its complement.
Therefore,x = 8(90-x)
x = 720-8x
x+8x = 720
9x = 720
x = 720/9
x = 80.

1 solutions

Answer 320828 by nerdybill(6948) About Me  on 2011-07-06 10:02:05 (Show Source):
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An angle is equal to eight times its complement. Determine its measure.
.
Let x = the angle
then
90-x = complement of angle
.
x = 8(90-x)
x = 720-8x
8x = 720
x = 90 degrees


Triangles/467557: What is the area of a rectangle measuring 25 ft long by 8 ft wide?
1 solutions

Answer 320827 by nerdybill(6948) About Me  on 2011-07-06 09:59:41 (Show Source):
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25 * 8 = 200 square feet


decimal-numbers/467515: what does exact mean?
1 solutions

Answer 320820 by nerdybill(6948) About Me  on 2011-07-06 08:54:20 (Show Source):
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It means that you leave your answer in the form of a fraction or radicals (square root symbol) -- instead of a decimal answer.


Travel_Word_Problems/467154: An Airplane travels in 5hrs. with a speed of 50km/hr. How far does it travel?

1 solutions

Answer 320623 by nerdybill(6948) About Me  on 2011-07-05 15:27:14 (Show Source):
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An Airplane travels in 5hrs. with a speed of 50km/hr. How far does it travel?
.
Distance formula:
d = rt
d = 50*5
d = 250 km


Pythagorean-theorem/466699: the diagonal of a square is 24 centimeter.how long is the side of the square/

1 solutions

Answer 320093 by nerdybill(6948) About Me  on 2011-07-03 16:35:41 (Show Source):
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the diagonal of a square is 24 centimeter.how long is the side of the square
.
apply Pythagorean theorem:
Let x = length of side of square
then
x^2 + x^2 = 24
2x^2 = 24
x^2 = 12
x = sqrt(12)
x = sqrt(2*2*3)
x = 2*sqrt(3) centimeters (exact answer)
.
Or, decimal approx:
x = 3.46 centimeters



Polynomials-and-rational-expressions/466814: the question states, simpify be removing factors of 1. 9-z/z-9. this is what i got, (z+3)^2. i dont know if it is right so i was asking for some help please. thank you.
1 solutions

Answer 320089 by nerdybill(6948) About Me  on 2011-07-03 16:21:59 (Show Source):
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(9-z)/(z-9)
notice if I factor out a -1 from the numerator I get:
-1(-9+z)/(z-9)
then, if I reorder the terms inside the parenthesis:
-1(z-9)/(z-9)
Now, I can cancel like-terms leaving:
-1


Graphs/466574: Hello and thank you so much for your help.I got this function 7-6x-x^2=0 it's a parabola that crosses the x-axis on the points -7.0 and 1.0, the vertex it's at the point (-3.0,16). I need to find the equation of the axis of symmetry for this parabola. Thank you again and have a happy 4th of July.
1 solutions

Answer 319891 by nerdybill(6948) About Me  on 2011-07-02 15:17:05 (Show Source):
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Hello and thank you so much for your help.I got this function 7-6x-x^2=0 it's a parabola that crosses the x-axis on the points -7.0 and 1.0, the vertex it's at the point (-3.0,16). I need to find the equation of the axis of symmetry for this parabola. Thank you again and have a happy 4th of July.
.
You can derive the axis of symmetry from the vertex and "inspecting" the original equation.
First,
Determine whether it is a "vertical" or a "horizontal" parabola. If your equation has a x^2 term -- it is a "vertical" parabola.
Second,
Once you know this, then you can simply use the x-coordinate of the vertex. So, the axis of symmetry is then
x = -3 (vertical line crossing the x-axis at -3)
.
Note:
the axis of symmetry is also derived by:
-b/(2a)
where
'a' and 'b' are the coefficients of the original equation


test/466389: ab= 6b + cd (Solve for a)
1 solutions

Answer 319797 by nerdybill(6948) About Me  on 2011-07-01 22:59:09 (Show Source):
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ab= 6b + cd (Solve for a)
divide both sides by b:
(ab)/b= (6b + cd)/b
a = (6b + cd)/b
a = 6 + cd/b


Probability-and-statistics/466368: there are 9 books 55% of 9 books are out,how many are left? solve this problem using a proportion show all steps.and explain
1 solutions

Answer 319736 by nerdybill(6948) About Me  on 2011-07-01 18:47:14 (Show Source):
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there are 9 books 55% of 9 books are out,how many are left? solve this problem using a proportion show all steps.and explain
.
since 55% are out
100-55 = 45% are left
.
Let x = books left
then
x/9 = 45/100 (this is your proportion)
cross multiplying:
100x = 9*45
100x = 405
x = 4.05
since you can't have fractional book, you have to round down:
there are 4 books left


Travel_Word_Problems/466408: How many hours will it take to travel 130 miles at 70 miles per hour?
1 solutions

Answer 319734 by nerdybill(6948) About Me  on 2011-07-01 18:40:53 (Show Source):
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How many hours will it take to travel 130 miles at 70 miles per hour?
Apply the "distance formula"
d = rt
where
d is 130
r is 70
.
130 = (70)t
130/70 = t
1.86 hours = t
or
1 hour and 51 minutes