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Graphs/613282: I need to show the graph of this function....
f(x)=|x|
1 solutions

Answer 385927 by ewatrrr(10682) About Me  on 2012-05-21 11:33:01 (Show Source):
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Hi,
f(x)=|x| Note: f(x) ≥ 0



Sequences-and-series/613268: Find the sum of the first four terms of the geometric sequence that starts with 3 and has r = 8.
Find the sum of the following infinite geometric series, if it exists.
4 + 3 + 2.25 + 1.6875 +…
1 solutions

Answer 385926 by ewatrrr(10682) About Me  on 2012-05-21 11:19:49 (Show Source):
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Hi,
Find the sum of the first four terms of the geometric sequence that starts with 3 and has r = 8.
sum%28+a%5Bn%5D%2C+n=1%2C+4+%29+=+a%5B1%5D%28%281-8%5E4%29%2F%281-8%29%29 = 3(-4095/-7) = 1755
Find the sum of the following infinite geometric series, if it exists.
4 + 3 + 2.25 + 1.6875 +…
sum%28+4%283%2F4%29%5E%28n-1%29%2C+i=1%2C+infinity+%29 = a%5B1%5D%2F%281-r%29 = 4%2F%281%2F4%29 = 16


�t�e�s�t/613271: When the digits of a two-digit number are reversed, the result is another two-digit number that is 62.5% smaller than the original number. What is the original number ?
1 solutions

Answer 385924 by ewatrrr(10682) About Me  on 2012-05-21 10:59:13 (Show Source):
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Hi,
Let x and y represnt the ten and unit digits of the original number.
Note: .625 = 5/8
When the digits of a two-digit number are reversed, the result is
another two-digit number that is 62.5% smaller than the original number
62.5% smaller or 3/8 of original number
10y + x = (3/8)(10x+y)
80y + 8x = 30x + 3y
77y = 22x
7/2 = x/y
Original number is 72
27 = 3/8(72)


�t�e�s�t/613269: The mean of the first four terms in an arithmetic sequence is 77. When the fifth and sixth terms are included, the mean increases by 32. What is the first term in this sequence?
1 solutions

Answer 385920 by ewatrrr(10682) About Me  on 2012-05-21 10:34:15 (Show Source):
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Hi,
Note: S%5Bn%5D=%28n%2F2%29%282%2Aa%5B1%5D%2B+%28n-1%29d%29
S%5B6%5D=+654%2F3+=%282%2Aa%5B1%5D%2B+5d%29
S%5B4%5D=+308%2F2+=%282%2Aa%5B1%5D%2B+3d%29***
218 - 154 = 2d
32 = d
*** 154 = 2a[1] + 96
29 = a[1]
218 = 58 + 160


Quadratic_Equations/613262: Given the following revenue and cost functions, find the x-value that
makes profit a maximum. (Re2all that profit equals revenue minus cost.)
R(x) = 55x - 2x^2; C(x) = 21x + 98
1 solutions

Answer 385919 by ewatrrr(10682) About Me  on 2012-05-21 10:21:13 (Show Source):
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Hi,
R(x) = 55x - 2x^2
C(x) = 21x + 98
P(x) = 55x - 2x^2 -(21x + 98)
P(x) = -2x^2 + 34x - 98
x = 8.5 makes max profit


Miscellaneous_Word_Problems/613260: This one has me stumpted! Could someone explain?
A cyclindrical aquarium is designed with a base diameter of 5 feet and a height of 6 feet. If 3.14 is used for pie, what is the approximate volume of the aquarium to the nearest cubic foot.
A. 38
B. 118
C. 471
D. 1,884



1 solutions

Answer 385918 by ewatrrr(10682) About Me  on 2012-05-21 10:07:49 (Show Source):
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Hi,

cyclindrical aquarium is designed with a base diameter of 5 feet and a height of 6 feet.
V = pi%2Ar%5E2h+=+3.14%2A%282.5%29%5E2%2A6 = 118 ft^3, rounded to the nearest whole number


test/613240: At 10 weeks old a puppy weighs 9 pounds. At 30 weeks old the puppy weighs 24 pounds. Assume that puppy weight is a linear function in time in weeks for the first year. If thou opt growth is graphed with weeks on the x axis and pounds on the y axis, what is the slope of the graph? What is an equation of the line? How much did the puppy weigh when it was born? At what age will the puppy weigh 30 pounds?
1 solutions

Answer 385916 by ewatrrr(10682) About Me  on 2012-05-21 09:59:33 (Show Source):
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Hi,
At 10 weeks old a puppy weighs 9 pounds. At 30 weeks old the puppy weighs 24 pounds
(30,24)
(10,9) m = 13%2F20
y = (13/20)x + b
9 = (13/20)10 + b
5/2 = b
y+=+%2813%2F20%29x+%2B+5%2F2 when born (x=0) weighed 2.5 lbs
30+=+%2813%2F20%29x+%2B+5%2F2
%2855%2F2%29%2820%2F13%29=+x
At 42.3 wks, puppy will weigh 30lbs



Probability-and-statistics/613243: Roll a pair of dice.
What is the probability you roll a 12 given you have rolled higher than a nine?
1 solutions

Answer 385909 by ewatrrr(10682) About Me  on 2012-05-21 09:24:37 (Show Source):
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Hi, Re:TY,
The display below are the 36 possible outcomes rolling a pair of dice
Only one of the outcomes is >9 'and' is a 12, thus the 1/36
There are 6 possible outcomes >9 and therefore the 6/36
P(A|B) = P(A and B)/P(B)
P(12|>9) = %281%2F36%29%2F%286%2F36%29 = 1/6
___1_2_3__4__5__6
1|_2_3_4__5__6__7
2|_3_4_5__6__7__8
3|_4_5_6__7__8__9
4|_5_6_7__8__9_10
5|_6_7_8__9_10_11
6|_7_8_9_10_11_highlight%2812%29


Numbers_Word_Problems/613245: is -1 larger than -100
1 solutions

Answer 385907 by ewatrrr(10682) About Me  on 2012-05-21 09:20:21 (Show Source):
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Hi,
is -1 larger than -100
picture the numbers on a Number line: Yes, -1 is larger than-100
number_line%28+600%2C+-110%2C+10%2C+-1%2C-100+%29


Proportions/613229: A student's grade in a course is determined by 4 quizzes and 1 exam. If the exam counts twice as much as each of the quizzes, what fraction of the final grade is determined by the exam?
1 solutions

Answer 385905 by ewatrrr(10682) About Me  on 2012-05-21 09:17:14 (Show Source):
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Hi,
x + x + x + x + 2x = 1
6x = 1
x = 1/6, fraction of the final grade determined by each quiz
Exam is 2(1/6) = 1/3
1/6 + 1/6 + 1/6 + 1/6 + 1/3 = 4/6 + 1/3 = 1


Proportions/613230: There are 3 to 4 tablespoons of bread flour in 1 ounce. What is the maximum number of tablespoons of bread flour in 12 ounces?
A)8
B)12
C)36
D)42
E)48
1 solutions

Answer 385898 by ewatrrr(10682) About Me  on 2012-05-21 08:48:54 (Show Source):
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Hi,
Am assuning You meant 12 'ounces'
Letting x represent the maximum number of tablespoons of bread flour in 12 ounces:
4TBSP%2F1oz+=+x%2F12oz |Cross Multiplying to solve
x = 48 TBSP, the maximum number of tablespoons of bread flour in 12 ounces


Probability-and-statistics/613215: Please show me how to construct a scatterplot for the (x, y) values below, and answer the following questions.
x y

1 1.5

2 3.0

3 4.5

4 6.0

5 7.5

What would be the slope of this regression line?
Would the correlation between x and y be positive or negative?
How would you interpret these data in terms of linear regression?

1 solutions

Answer 385897 by ewatrrr(10682) About Me  on 2012-05-21 08:44:41 (Show Source):
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Hi,
(4,6)
(2,3) m = 3/2
positve correlation
scatter plot of this data shows a linear regression: y = (3/2)x



Quadratic-relations-and-conic-sections/613188: How do I plug in a translated hyperbola equation into my graphing calculator? For example, (y-3)^2/(4) - (x+1)^2/(9) = 1 ?
1 solutions

Answer 385894 by ewatrrr(10682) About Me  on 2012-05-21 08:16:14 (Show Source):
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Hi,
(y-3)^2/(4) - (x+1)^2/(9) = 1
y = 3 +(2)sqrt(1+(x+1)^2/9)
y = 3 -(2)sqrt(1+(x+1)^2/9)


Sequences-and-series/613013: write a rulefor the nth termof the arithmetic sequence..
problem #1...a11=29;a20=101
that is a 11
problem #2 a6=-31;a14=-135

Thank you


1 solutions

Answer 385852 by ewatrrr(10682) About Me  on 2012-05-20 18:16:46 (Show Source):
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Hi,
a%5B20%5D=+101+=+a%5B1%5D%2B%2819%29%2Ad
a%5B11%5D=+29+=++a%5B1%5D%2B%2810%29%2Ad
72 = 9d
8 = d
29+=+a%5B1%5D+%2B+80
-51+=+a%5B1%5D
a%5Bn%5D=+-51+%2B%28n-1%29%2A8
OR
a%5Bn%5D=+8n-59


Linear-equations/613010: Write thd equation of the line passing through (4,7) and parallel to 6x-7y=10
1 solutions

Answer 385850 by ewatrrr(10682) About Me  on 2012-05-20 18:08:31 (Show Source):
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Hi,
equation of the line passing through (4,7) and parallel to 6x-7y=10 OR y = (6/7)x -10/7
y = (6/7)x + b
7 = (6/7)4 + b ||Using pt(4,7) to solve for b
25/7 = b
y = (6/7)x + 25/7 or in Standard form: 6x-7y = -25


Distributive-associative-commutative-properties/613006: (6+3i)(6-3i)
1 solutions

Answer 385849 by ewatrrr(10682) About Me  on 2012-05-20 18:03:46 (Show Source):


Quadratic_Equations/613004: Use graph to estimate roots of this quadratic equation:
-x^2+3x-2=0
1 solutions

Answer 385848 by ewatrrr(10682) About Me  on 2012-05-20 18:01:05 (Show Source):
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Hi,
My recommendation would be to Plot 'easy Pts'...using for ex: x = 0,1,2
and sketch the parabola



Quadratic-relations-and-conic-sections/612997: Need help on writing the standard form of the equation:+y%5E2-x%2B2y%2B3=0
I tryed it out by completing the square this is what I done:
+y%5E2-x%2B2y%2B3=0
+y%5E2%2B2y-x%2B3=0 grouped the y terms together
y%5E2%2B2y%2B1=+x-3+%2B1 divided 2 by -2 and squared it, moved x+3 to the right and added 1 to both sides.
%28y%2B1%29%5E2+=+x-2+ that's the last part I got. Am I on the right track? I think it's supposed to be a parabola.
Please show your steps on how to get the answer.

1 solutions

Answer 385845 by ewatrrr(10682) About Me  on 2012-05-20 17:37:08 (Show Source):
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Hi,
+y%5E2-x%2B2y%2B3=0
%28y%2B1%29%5E2+=+x-2+ Yes!!!
%28y%2B1%29%5E2+%2B2+=+x+
Parabola opening right, Vertex (2,-1)


Travel_Word_Problems/612989: Two buses start from the same station and drive in opposite directions. The expressbus is traveling 10 mph fster than the local bus. In 3 hours the buses are 300 miles apart. Find the rate of each bus.
1 solutions

Answer 385842 by ewatrrr(10682) About Me  on 2012-05-20 17:32:43 (Show Source):
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Hi,
express bus is traveling 10 mph faster than the local bus
Let x and (x+10) represent speeds of local and express respectively
Question states*** D = rt
3x + 3(x+10) = 300mi
6x = 270
x = 45mph, speed of local train. Express is 55mph


Geometry_Word_Problems/612982: The area of a rectangle is 96 square centimeters. If the width of the rectangle is 4 centimeters less than its length, what are the dimensions of the rectangle?
1 solutions

Answer 385839 by ewatrrr(10682) About Me  on 2012-05-20 17:29:15 (Show Source):
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Hi,
width of the rectangle is 4 centimeters less than its length
Let x and (x-4) represent length and width respectively
Question states***
x(x-4)= 96 in^2
x^2 - 4x - 96 = 0
(x-12)(x+8) = 0
x = 12, throwing out negative solution for unit measure
Length is 12cm and width is 8cm
12in*8in = 96cm^2


Quadratic-relations-and-conic-sections/612978: Whats the standard form of the equation : +y%5E2-x%2B2y%2B3=0+ . By completing the square. Also what type of conic would it be?
Please show the steps.
1 solutions

Answer 385835 by ewatrrr(10682) About Me  on 2012-05-20 17:22:11 (Show Source):
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Hi,
+y%5E2-x%2B2y%2B3=0+
%28y%2B1%29%5E2+-1+-x+%2B+3+=+0
%28y%2B1%29%5E2+%2B+2+=+x+
Parabola opening right Vertex(2,-1)



Radicals/612981: I have been trying to figure out this math problem for a while.
It says Jeff takes 5hrs longer to build a fence than it takes Bill. When they work together, it takes them 6 hours. How long would it take Bill to do the job alone? So far I have
1/x-5 + 1/x = 1/6
I am not sure were to go from there thank you
1 solutions

Answer 385832 by ewatrrr(10682) About Me  on 2012-05-20 17:15:36 (Show Source):
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Hi,
Jeff takes 5hrs longer to build a fence than it takes Bill.
Letting x and (x+5) represent Bill's and Jeff's times respectively
PER HOUR Key:
1%2F%28x%2B5%29+%2B+1%2Fx+=+1%2F6 Yes!!
Multiplying thru with 6x(x+5) so as all denominators= 1
6x + 6(x+5) = x(x+5)
12x +30= x^2 + 5x
x^2 - 7x - 30
factoring:
(x-10)(x+3)= 0
x = 10 , x = -3 Throwing out x = -3
x = 10hr is Bill's time and Jeff's is 15hr
1/10 +1/15 = 25/150 = 1/6


Money_Word_Problems/612964: What is the total amount for an investment of $100 invested at 3.5% for 8 years and compounded continuously?
1 solutions

Answer 385827 by ewatrrr(10682) About Me  on 2012-05-20 16:46:03 (Show Source):
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Hi,
total amount for an investment of $100 invested at 3.5% for 8 years and compounded continuously?
A = 100%2Ae%5E%28.035%2A8%29 = $132.31


Permutations/612955: How many different 10 letters word (real or imaginary) can be formed from the following letters TPIOOYPUTM
______ten letter words (real or imaginary can be formed with the giver letters.
1 solutions

Answer 385822 by ewatrrr(10682) About Me  on 2012-05-20 16:36:47 (Show Source):
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Hi,
How many different 10 letters word (real or imaginary) can be formed from the following letters TPIOOYPUTM
TPIOOYPUTM has 2-Ts,2-Ps, 2-Os
10!/(2!2!2!) = 453,600 ways


Quadratic-relations-and-conic-sections/612923: The equation of the hyperbola that has a center at (10,4), a focus at (15,4), and a vertex at (13,4)
1 solutions

Answer 385806 by ewatrrr(10682) About Me  on 2012-05-20 15:48:02 (Show Source):
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Hi,
hyperbola that has a center at (10,4), a focus at (15,4), and a vertex at (13,4)
Opens right and left,Distance of the vertices from center = 3 %28x-10%29%5E2%2F3%5E3+-+%28y-4%29%5E2%2Fb%5E2+=+1
Distance of the foci from center = 5 = sqrt%289%2Bb%5E2%29, b = 4
%28x-10%29%5E2%2F3%5E3+-+%28y-4%29%5E2%2F4%5E2+=+1


Money_Word_Problems/612877: Kim wants to buy a farm in ten years. It will cost $250,000. She is earning 8% returns on her investments. How much does she need to save at the end of each month in order to reach her goal?
1 solutions

Answer 385803 by ewatrrr(10682) About Me  on 2012-05-20 15:22:28 (Show Source):
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Hi,
In General A+=+P%5Bn%5D%28%281%2Br%2Fn%29%5E%28nt%29-1%29%2F%28r%2Fn%29
A = Accumulated Amount = 250,000
P[n]= Savings Amount per period
r= annual rate = .08
n= periods per year = 12
t= years = 10
250000+=+P%5B12%5D%28%281%2B.08%2F12%29%5E%2812%2A10%29-1%29%2F%28.08%2F12%29%29
250000%28.08%2F12%29+=+P%5B12%5D%28%281%2B.08%2F2%29%5E%2812%2A10%29-1%29
p%5B12%5D, the monthly savings amount necessary = $1366.52


Linear_Equations_And_Systems_Word_Problems/612803: 8 boys and 12 girls can finish the work in 10 days, while 6 boys and 8 girls can finish it in 14 days. Find the time taken by 1 boy alone and 1 girl alone to finish the work.
1 solutions

Answer 385759 by ewatrrr(10682) About Me  on 2012-05-20 12:11:34 (Show Source):
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Hi,
8 boys and 12 girls can finish the work in 10 days, while 6 boys and 8 girls can finish it in 14 days
Note: work PER Day KEY
Let x and y represent work done per day by boy and girl respectively:
8x + 12y = 1/10
6x + 8y = 1/14 |multiplying thru by -3/2 to eliminate the y variable
8x + 12y = 1/10
-9x -12y = -3/28 |result of multiplying thru by -3/2 to eliminate the y variable
x = 1/140 and y = 1/280, work PER Day by each
time taken by 1 boy alone140days and 1 girl alone280days to finish the work.


Quadratic-relations-and-conic-sections/612564: find the vertices, foci, and asymptote of 16x^2 - 25y^2=400
1 solutions

Answer 385565 by ewatrrr(10682) About Me  on 2012-05-18 17:30:35 (Show Source):
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Hi,
16x^2 - 25y^2=400
x%5E2%2F5%5E2+-+y%5E2%2F4%5E2=1
Note:Standard Form of an Equation of an Hyperbola is %28x-h%29%5E2%2Fa%5E2+-+%28y-k%29%5E2%2Fb%5E2+=+1 opening right or left
where Pt(h,k) is a center with vertices 'a' units right and left of center. V are (±5,0)
Asymptotes passing thru the center with slope = ± b/a , y = ±4/5x
foci being ± sqrt(a^2 + b^2) from center along axis of symmetry y = b
foci are (±sqrt%2841%29,0)



Probability-and-statistics/612553: 100 people surveyed 34 smoked, 61 cursed, 50 drank alcohol, 25 smoked and cursed, 30 cursed and drank alcohol, and 6 had all 3 habits.
a) How many had none of these habits
b) Only had the smoking habit

1 solutions

Answer 385563 by ewatrrr(10682) About Me  on 2012-05-18 17:15:44 (Show Source):
You can put this solution on YOUR website!
 
Hi, Hi re TY,
1) Note: no mention of the 8 who smoked and used alcohol...Note: says only highlight%2834%29 smokers total
2) 6 with all habits listed.
100 people surveyed 34 smoked, 61 cursed, 50 drank alcohol, 25 smoked and cursed,
30 cursed and drank alcohol, and 6 had all 3 habits.
a) How many had none of these habits: 22
b) Only had the smoking habit 3



test/612474: (-5,4) (-1,11)
1 solutions

Answer 385553 by ewatrrr(10682) About Me  on 2012-05-18 16:07:29 (Show Source):
You can put this solution on YOUR website!
 
Hi,
Find the slope of the line through each pair of points:


(-5,4)
(-1,11) m = -7/-4 = 7/4
y = (7/4)x + b ||Using Pt(-1,11) to solve for b
11 = (7/4)(-1) + b
51/4 = b
0 = b
y = (7/4)x + 51/4 OR in Standard form: 7x -4y = 51


test/612475: (-2,-8) (1,4)
1 solutions

Answer 385535 by ewatrrr(10682) About Me  on 2012-05-18 15:01:24 (Show Source):
You can put this solution on YOUR website!
 
Hi,
Find the slope of the line through each pair of points:


(-2,-8)
(1,4) m = -12/-3 = 4
y = 4x + b ||Using Pt(1,4) to solve for b
4 = 4*1 + b
0 = b
y = 4x OR in Standard form: 4x -y = 0