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Graphs/604847: Hello,
Would u pls, check my answer?
Factor the expression :c^2 + 4c + 4
My answer: (c + 2)^2
Thanks a lot,
H.H

1 solutions

Answer 381455 by nerdybill(7003) About Me  on 2012-04-29 11:03:51 (Show Source):
You can put this solution on YOUR website!
You are correct.
.
You can check yourself... apply FOIL on
(c + 2)(c + 2)
and will get your original expression


Linear-equations/604821: Just checking to see if I did this problem correctly.
Find the equation of the line that goes through the points (-4,1) and (-1,4)
I found the slope of -1/-1 or -1
y = x + b
4 = -1 + b
5 = b
answer y = x + 5 ??
1 solutions

Answer 381425 by nerdybill(7003) About Me  on 2012-04-29 08:19:18 (Show Source):
You can put this solution on YOUR website!
Your answer is correct. However, I'm not sure I followed how you got there.
.
slope of (-4,1) and (-1,4):
m = (y2-y1)/(x2-x1)
m = (4-1)/(-1-(-4))
m = (4-1)/(-1+4)
m = 3/3
m = 1
.
plug slope (above) and one point (-4,1) into "point-slope" form:
y - y1 = m(x - x1)
y - 1 = 1(x - (-4))
y - 1 = 1(x + 4)
y - 1 = x + 4
y = x + 5


Pythagorean-theorem/604717: A guy wire attached to the top of a
30-foot-long pole is anchored 10 feet from the base
of the pole, as illustrated in the figure. Find the
length of the guy wire to the nearest tenth of a foot
1 solutions

Answer 381376 by nerdybill(7003) About Me  on 2012-04-28 20:55:21 (Show Source):
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A guy wire attached to the top of a
30-foot-long pole is anchored 10 feet from the base
of the pole, as illustrated in the figure. Find the
length of the guy wire to the nearest tenth of a foot
.
Apply Pythagorean Theorem:
Let x = length (feet) of wire
then
x^2 = 10^2 + 30^2
x^2 = 100 + 900
x^2 = 1000
x = 31.623
rounded to nearest tenth:
x = 31.6 feet


logarithm/604740: log8(2x-1)=0
1 solutions

Answer 381375 by nerdybill(7003) About Me  on 2012-04-28 20:52:34 (Show Source):
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I'll assume you meant log base 8:
log8(2x-1)=0
(2x-1)=8^0
2x-1=1
2x=2
x = 1


Quadratic_Equations/604688: Rewrite the quadratic equation in standard form by completing the square.
f(x)=x^2+8x+14
Answer (f(x)= (x, plus or minus ___)^2 plus or minus ____
I have worked this to x, 4 as well as x, -4. I have also come up with x, +8.
Also for the second answer I have some up with +14 or sqrt 2.
1 solutions

Answer 381346 by nerdybill(7003) About Me  on 2012-04-28 18:16:17 (Show Source):
You can put this solution on YOUR website!
Rewrite the quadratic equation in standard form by completing the square.
f(x)=x^2+8x+14
.
f(x)=x^2+8x+14
f(x)=(x^2+8x)+14
f(x)=(x^2+8x+16)+14-16
f(x)=(x+4)(x+4)-2
f(x)=(x+4)^2-2 (this is the standard form)


logarithm/604691: Solve the logarithm equation log[4](x)+ log[4](6x-7)=log[4]5.
Give the exact answer in the form of a fraction.
x=____
I worked the problem and came up with two different fractions; I have x= 1/2 or x=5/3.

1 solutions

Answer 381343 by nerdybill(7003) About Me  on 2012-04-28 18:08:50 (Show Source):
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log[4](x)+ log[4](6x-7)=log[4]5
log[4](x)(6x-7)=log[4]5
(x)(6x-7)=5
6x^2 - 7x = 5
6x^2 - 7x - 5 = 0
6x^2 - 10x + 3x - 5 = 0
(6x^2 - 10x) + (3x - 5) = 0
2x(3x - 5) + (3x - 5) = 0
(3x - 5)(2x+1) = 0
x = {5/3, -1/2}
Since you can't take the log of a negative number, you can throw out -1/2 (extraneous) leaving:
x = 5/3


Travel_Word_Problems/604595: On Thursday September 8, 2011 Arkansas State Senator Bruce Holland was convicted of fleeing a police officer. He was reportedly going 110 miles per hour during a 17 mile chase. Rounding to the nearest minute, how long did the chase last?

1 solutions

Answer 381287 by nerdybill(7003) About Me  on 2012-04-28 11:49:52 (Show Source):
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On Thursday September 8, 2011 Arkansas State Senator Bruce Holland was convicted of fleeing a police officer. He was reportedly going 110 miles per hour during a 17 mile chase. Rounding to the nearest minute, how long did the chase last?
.
Assuming he was traveling at 110 mph the entire time of the 17 mile chase (which, I'm sure he wasn't) then:
17/110 = .155 hours
or, about 9 minutes


Sequences-and-series/604590: I need help finding the vertex of the parabola: y= -6.25x²+ 150x + 7200?
I have graphed it and found the vertex to be (12, 8100) but I need to be able to find it algebraically. I tried taking the derivative but I'm not sure I was doing that right or if thats how I should approach it. Please explain your steps, so that i can learn what and why you are doing what you do. Thanks in advance for all the help.
1 solutions

Answer 381284 by nerdybill(7003) About Me  on 2012-04-28 11:40:24 (Show Source):
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y= -6.25x²+ 150x + 7200
.
The x-value of the vertex is at:
x = -b/(2a) (from the "quadratic formula" w/o the radical)
x = -150/(2(-6.25)
x = -150/(-12.5)
x = 150/12.5
x = 12
.
To find the y-value, plug the above back into the equation:
y= -6.25x²+ 150x + 7200
y= -6.25(12)²+ 150(12) + 7200
y= 8100


Linear-equations/604571: how do i find the x and y intercepts and slope of the equation 3x = -2
1 solutions

Answer 381276 by nerdybill(7003) About Me  on 2012-04-28 11:09:00 (Show Source):
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how do i find the x and y intercepts and slope of the equation 3x = -2
.
3x = -2
x = -2/3
This is simply a vertical line that crosses the x-axis at -2/3
.
x-intercept is at (0,-2/3)
y-intercept (none) runs parallel to the y-axis
slope is undefined since it is a vertical line


Rational-functions/604565: Can anyone help me figure this question out? Thanks!
Simplify by removing factors of 1
48v^10x^4/18v^4x^2
1 solutions

Answer 381274 by nerdybill(7003) About Me  on 2012-04-28 11:06:30 (Show Source):
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Simplify by removing factors of 1
48v^10x^4/18v^4x^2
(6*8)v^10x^4/(6*3)v^4x^2
8v^10x^4/3v^4x^2
8v^4v^6x^4/3v^4x^2
8v^6x^4/3x^2
8v^6x^2x^2/3x^2
8v^6x^2/3


Rational-functions/604580: f(x)= 3(x^2+5) Find f^-1(x), f^-1(27)
1 solutions

Answer 381273 by nerdybill(7003) About Me  on 2012-04-28 10:56:19 (Show Source):
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f(x)= 3(x^2+5) Find f^-1(x), f^-1(27)
.
Find f^-1(x):
y = 3(x^2+5)
switch the variables and solve for y:
x = 3(y^2+5)
x/3 = y^2+5
x/3 - 5 = y^2
sqrt(x/3 - 5) = y
or
f%5E-1%28x%29+=+sqrt%28x%2F3+-+5%29
.
finding f^-1(27):
f%5E-1%28x%29+=+sqrt%28x%2F3+-+5%29
f%5E-1%2827%29+=+sqrt%2827%2F3+-+5%29
f%5E-1%2827%29+=+sqrt%289+-+5%29
f%5E-1%2827%29+=+sqrt%284%29
f%5E-1%2827%29+=+2 (that's plus or minus 2)


Travel_Word_Problems/604575: Two cars leave town at the sime time traveling in opposite dirrections. One travels 70 mi/h and the other 55 mi/h. In how many hours will they be 250 miles apart?
1 solutions

Answer 381272 by nerdybill(7003) About Me  on 2012-04-28 10:50:24 (Show Source):
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Two cars leave town at the sime time traveling in opposite dirrections. One travels 70 mi/h and the other 55 mi/h. In how many hours will they be 250 miles apart?
apply the distance formula of d=rt
.
Let x = time (hours) traveled
then
70x + 55x = 250
125x = 250
x = 250/125
x = 2 hours


Polynomials-and-rational-expressions/604572: Classify the polynomial as constant, linear, quadratic, cubic, or quartic, and determine the leading term, the leading coefficient, and the degree of the polynomial.
f(x)=14-x^2
1 solutions

Answer 381271 by nerdybill(7003) About Me  on 2012-04-28 10:45:27 (Show Source):
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Classify the polynomial as constant, linear, quadratic, cubic, or quartic, and determine the leading term, the leading coefficient, and the degree of the polynomial.
f(x)=14-x^2
Ordered in highest to lowest degree:
f(x) = -x^2+14
.
It is a "quadratic".
Leading term: -x^2
Leading coefficient: -1
Degree: 2


Functions/604578: State the domain of the rational function.
g(x)= x-8/x+3
1 solutions

Answer 381269 by nerdybill(7003) About Me  on 2012-04-28 10:41:27 (Show Source):
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State the domain of the rational function.
g(x)= x-8/(x+3)
.
The "domain" specifies all possible values of x.
In this case, you just want to make sure the denominator is not zero because dividing by zero is undefined.
So, we set the denominator to zero to find the value x can't take:
x+3=0
x = -3
So, the domain is all real numbers except -3. Or, you can state it like:
(-oo, -3) U (-3, +oo)
where
oo stands for infinity


Functions/604574: For the function find the maximum number of real zeros that the function can have, the maximum number of x-intercepts that the function can have, and the maximum number of turning points that the graph of the function can have.
f(x)=5x^3+8x^2-2x+9
1 solutions

Answer 381267 by nerdybill(7003) About Me  on 2012-04-28 10:35:03 (Show Source):
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For the function find the maximum number of real zeros that the function can have, the maximum number of x-intercepts that the function can have, and the maximum number of turning points that the graph of the function can have.
f(x)=5x^3+8x^2-2x+9
.
Max number of real zeros: 3
Max number of x-intercepts: 3
max turning points: 3-1 = 2


Travel_Word_Problems/604568: An airliner travels 35 miles in 4 minutes. What is its speed in miles per hour?
1 solutions

Answer 381264 by nerdybill(7003) About Me  on 2012-04-28 09:55:51 (Show Source):
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35 miles in 4 minutes:
35/4 miles/min * 60 min/hr
(35*60)/4
2100/4
525 miles per hour (mph)


Geometry_Word_Problems/604554: suppose that 500 people attended the play if adults were charged 10 dollars and children were charged 7 dollars determine how many adults and children attended if they raised a total of 4472 dollars
1 solutions

Answer 381263 by nerdybill(7003) About Me  on 2012-04-28 09:53:34 (Show Source):
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suppose that 500 people attended the play if adults were charged 10 dollars and children were charged 7 dollars determine how many adults and children attended if they raised a total of 4472 dollars
.
Let x = number of adults
then
500-x = number of children
.
10x + 7(500-x) = 4472
10x + 3500-7x = 4472
3x + 3500 = 4472
3x = 972
x = 324 (adults)
.
Children:
500-x = 500-324 = 176


Angles/604567: the measure of the supplement of an angle is 40 less than 3 times its complement, find the measure of the angle, its supplement and its complement, please give me the formula and how you figured it out. thanks so much.
1 solutions

Answer 381262 by nerdybill(7003) About Me  on 2012-04-28 09:49:12 (Show Source):
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the measure of the supplement of an angle is 40 less than 3 times its complement, find the measure of the angle, its supplement and its complement, please give me the formula and how you figured it out. thanks so much.
.
Let x = the angle
then
90-x = the complement
180-x = the supplement
.
From: "the supplement of an angle is 40 less than 3 times its complement" we get our equation:
180-x = 3(90-x) - 40
180-x = 270-3x - 40
180-x = 230-3x
180+2x = 230
2x = 50
x = 25 degrees (the angle)
.
The complement:
90-x = 90-25 = 65 degrees
.
The supplement:
180-x = 180-25 = 155 degrees


Equations/604542: lisa can sweep the paths around her home in 30 minutes. Her sister Tania takes 20 minutes to do the same job. If they work together, how long will it take to complete the job?
1 solutions

Answer 381261 by nerdybill(7003) About Me  on 2012-04-28 09:45:08 (Show Source):
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lisa can sweep the paths around her home in 30 minutes. Her sister Tania takes 20 minutes to do the same job. If they work together, how long will it take to complete the job?
.
Let x = time (minutes) it takes for both
then
x(1/30 + 1/20) = 1
multiplying both sides by 60 (common denominator) we get:
x(2 + 3) = 60
x(5) = 60
x = 60/5
x = 12 minutes


logarithm/604562: what is one less than 3000 in base 5. Please show step by step
1 solutions

Answer 381260 by nerdybill(7003) About Me  on 2012-04-28 09:42:47 (Show Source):
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what is one less than 3000 in base 5. Please show step by step
.
Begin by converting 3000 base 5 to base 10:
3*5^3
3*125
375
one less than the above is then:
374
.
Or, you could do the math in base 5:
3000-1 = 2444 in base 5
converting to base 10
2*5^3 + 4*5^2 + 4*5 + 4
2*125 + 4*25 + 4*5 + 4
250 + 100 + 20 + 4
374




Linear_Equations_And_Systems_Word_Problems/604444: you order 2 tacos and 2 enchiladas for $4.80. you friend order 3 tacos and 1 enchiladas for $4. how much does each cost
1 solutions

Answer 381161 by nerdybill(7003) About Me  on 2012-04-27 18:43:35 (Show Source):
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you order 2 tacos and 2 enchiladas for $4.80. you friend order 3 tacos and 1 enchiladas for $4. how much does each cost
.
Let t = cost of a taco
and e = cost of an enchilada
.
2t + 2e = 4.80
3t + e = 4.00
.
multiply bottom equation by -2 and add both equations together:
2t + 2e = 4.80
-6t - 2e = -8.00
-------------------
-4t = -3.20
t = -3.20/(-4)
t = $0.80 (or 80 cents for a taco)
.
enchilada:
3t + e = 4.00
3(0.80) + e = 4.00
2.40 + e = 4.00
e = 4.00 - 2.40
e = $1.60


Rational-functions/604442: evaluate v(s)=s^3+3s^2-4s-2 when s = -2
1 solutions

Answer 381160 by nerdybill(7003) About Me  on 2012-04-27 18:38:58 (Show Source):
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evaluate v(s)=s^3+3s^2-4s-2 when s = -2
.
substitute the s for -2 in the equation:
v(s)=s^3+3s^2-4s-2
v(-2)=(-2)^3+3(-2)^2-4(-2)-2
v(-2)=-8+3(4)-(-8)-2
v(-2)=-8+12+8-2
v(-2)=4+8-2
v(-2)=12-2
v(-2)=10


Volume/604379: how can I find the base of a figure if the volume is 210 ft³ and the height is 14 ft?
1 solutions

Answer 381155 by nerdybill(7003) About Me  on 2012-04-27 16:48:53 (Show Source):
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how can I find the base of a figure if the volume is 210 ft³ and the height is 14 ft?
.
Volume = "area of base" * " height"
plug in what was given:
210 = b(14)
210/14 = b
15 square feet = b (base area)


test/604410: log(2x+5)=3
1 solutions

Answer 381153 by nerdybill(7003) About Me  on 2012-04-27 16:45:48 (Show Source):
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log(2x+5)=3
2x+5=10^3
2x+5=1000
2x=995
x = 995/2
x = 497.5


Square-cubic-other-roots/604351: How do you simplify a radical of 45
1 solutions

Answer 381111 by nerdybill(7003) About Me  on 2012-04-27 12:59:17 (Show Source):
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sqrt%2845%29
factor (using prime numbers):
sqrt%285%2A9%29
sqrt%285%2A3%2A3%29
then, for pull out "pairs":
3sqrt%285%29


Percentage-and-ratio-word-problems/604345: how do you convert 40.8% to a fraction in lowest terms?
1 solutions

Answer 381110 by nerdybill(7003) About Me  on 2012-04-27 12:53:51 (Show Source):
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how do you convert 40.8% to a fraction in lowest terms?
since % is "per one hundred" we have:
40.8/100
multiply both numerator and denominator by 10:
408/1000
then, we reduce the fraction:
204/500
102/250
51/125


Probability-and-statistics/604272: IQ test scores are normally distributed with a mean of 100 and a standard deviation of 15
The z-score for an IQ score of 112 is -0.8
true or false
1 solutions

Answer 381074 by nerdybill(7003) About Me  on 2012-04-27 09:02:48 (Show Source):
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IQ test scores are normally distributed with a mean of 100 and a standard deviation of 15
The z-score for an IQ score of 112 is -0.8
.
z = (dataPoint - mean)/stdDev
z = (112-100)/15
z = 12/15
z = .8
.
Answer: false


Probability-and-statistics/604273: IQ test scores are normally distributed with a mean of 100 and a standard deviation of 15
If the z-score on your IQ score was 1.3, then you had a score of 119.5
true or false
1 solutions

Answer 381073 by nerdybill(7003) About Me  on 2012-04-27 09:00:35 (Show Source):
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IQ test scores are normally distributed with a mean of 100 and a standard deviation of 15
If the z-score on your IQ score was 1.3, then you had a score of 119.5
.
z = (dataPoint - mean)/stdDeviation
z = (119.5 - 100)/15
z = (19.5)/15
z = 1.3
.
Answer: true


logarithm/604266: Solve for x: log base 5 (x^2+4x+4)=2
1 solutions

Answer 381068 by nerdybill(7003) About Me  on 2012-04-27 08:44:43 (Show Source):
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Solve for x:
log base 5 (x^2+4x+4)=2
x^2+4x+4 = 5^2
x^2+4x+4 = 25
x^2+4x-21 = 0
(x+7)(x-3) = 0
x = {-7, 3}


Exponential-and-logarithmic-functions/604159: log base 1/3 27
what do you raise 1/3 to to get 27(I think this is how to read the problem)
Can anyone explain how to get the answer please.
Thank you

1 solutions

Answer 380993 by nerdybill(7003) About Me  on 2012-04-26 23:01:36 (Show Source):


Polynomials-and-rational-expressions/604166: r^2+6r-27
1 solutions

Answer 380987 by nerdybill(7003) About Me  on 2012-04-26 22:48:36 (Show Source):
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r^2+6r-27
(r+9)(r-3)