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Answer 187643 by drk(1908) on 2010-01-10 14:58:22 (Show Source):
You can put this solution on YOUR website!let x = positive odd integer and x + 2 be the next positive odd integer.
we get
x^2 + (x+2)^2 = 202
foiling the left and combining like terms, we get
2x^2 + 4x + 4 = 202
and then
2x^2 + 4x - 198 = 0
divide by 2 to get
x^2 + 2x - 99 = 0
factor to get
(x+11)(x-9) = 0
solving for x, we get
x = -11 and x = 9
we get (-11,-9) OR (9,11)
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Probability-and-statistics/255362: The probability that an American CEO can transact business in a foreign language is .20. Ten
American CEOs are chosen at random. (a) What is the probability that none can transact business
in a foreign language? (b) That at least two can? (c) That all 10 can? (d) Sketch the probability
distribution and discuss its appearance. 1 solutions
Answer 187640 by drk(1908) on 2010-01-10 14:53:17 (Show Source):
You can put this solution on YOUR website!P(speak foreign language) = .20
P(NOT speak foreign language) = .80
(a) What is the probability that none can transact business in a foreign language?
answer: we want zero "YES" and 10 "NO" so,
nCr*(no)^10*(yes)^0
or
10c0*.8^10*.2^0 ~ .1074
--
(b) That at least two can?
answer: This means that 0 or 1 cannot. It is easier to do this in negation.
1 - p(0 not) + p(1 not) = 1 - 10c0(.8)^0*(.2)^10 + 10c1*(.8)^1*(.2)^9 ~ .99999
--
(c) That all 10 can?
answer; we want all 10 yes, so,
10c10*(.2)^10 ~ 1.02 x 10^-7
(d) Sketch the probability distribution and discuss its appearance.
The sketch should be a normal curve with cum sum = 1.
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Human-and-algebraic-language/255365: What is the slope of a line that is perpendicular to a line that has no slope? Explain the answer. 1 solutions
Answer 187634 by drk(1908) on 2010-01-10 14:40:55 (Show Source):
You can put this solution on YOUR website!If a line has no slope then it can be expressed as 1/0 or in general as a/0, where a not = 0.
A perpendicular slope is the negative reciprocal.
So, 1/0 turns into -0/1 = 0,
or in general a/0 turns into -0/a = 0.
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Quadratic_Equations/255366: (x*-3x)+8=0
cant figure out how to do the last part of question after I get here
x= 3 + - square root -23 over 2 1 solutions
Answer 187632 by drk(1908) on 2010-01-10 14:37:33 (Show Source):
You can put this solution on YOUR website!Your original equation was:

suppose * = 2. then we have a quadratic of the form

which can easily be solved using the quadratic formula as

which is simplified as

From here you have one of two ways to go.
(1) if you have never been shown imaginary numbers, then say no solution.
(2) If you have been shown imaginary numbers, then say
 ,
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Exponents/255363: please help me solve this problem... 4^x=(1/2)^3x+5 1 solutions
Answer 187630 by drk(1908) on 2010-01-10 14:33:05 (Show Source):
You can put this solution on YOUR website!If you mean
 , then
simplify as
 .
multiplying both sides by 8^x, we get

in this case, there is no x value which is true.
--
If you mean

simplifies as
 .
Multiply both sides by 8 to get

In this case, there is no x value which is true.
--
If you mean

then rewrite the right side as

the 4 can be expressed as 2^2, so we get

cancel the base 2's to get

solve for x to get
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Angles/255357: The measure of the supplement of an angle exceeds three times the measure of half the compliment of the angle by 12. Find the measure of half the supplement 1 solutions
Answer 187625 by drk(1908) on 2010-01-10 14:20:04 (Show Source):
You can put this solution on YOUR website!Let x be an angle.
180-x is the supplement.
90 - x is the compliment.
So, we get

By distributive prperty, we get

combining like terms on the right we get

and simplifying we get

The supplement of 66 is 114. Half of 114 is 57.
So answer is 57.
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Graphs/255361: how do i write an equation in slope-intercept form for the lone that is perpendicular to the given lone and passes through the given point
y=-3x+4;(6,-2) 1 solutions
Answer 187624 by drk(1908) on 2010-01-10 14:15:41 (Show Source):
You can put this solution on YOUR website!step 1 - solve the equation for y. That is already done and given as
(i) 
step 2 - find the slope of (i) and we get m = 3.
step 3 find perpendicular slope. m = 3, so perpendicular means flip and change sign. Perp m = -1/3.
step 4 - using new slope and (6,-2) we put that information into
 to get

step 5 - write the answer as
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Travel_Word_Problems/255359: Two airplanes start toward each other at the same time from airports located 1950 km apart. One plane flies at an average speed of 360 km/h. What should the average speed of the plane be if they meet in 3 hours? Show all work. 1 solutions
Answer 187621 by drk(1908) on 2010-01-10 14:07:29 (Show Source):
You can put this solution on YOUR website!This is a RTD problem. Here is the table based on given information:
airplane . . . . . . . . .rate . . . . . . . . .time . . . . . . . . .distance
A . . . . . . . . . . .. . . .360 . . . . . . . . .3 . . . . .. . . . . .. . 1080
B . . . . . . . . . . . . . . .R . . . . . . . . . . .3 . . . . . . .. . . . .. . 3R
totals . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 1950
The distance of A + distance of B = total distance. So,
1080 + 3R = 1950
3R = 870
R = 290 km/h
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Functions/255355: write in standard form, m= 5 and b = -5 1 solutions
Answer 187620 by drk(1908) on 2010-01-10 14:03:23 (Show Source):
You can put this solution on YOUR website!Lets start with slope intercept form as

we know m = 5 and b = -5, so we get
(i) 
standard form requires 2 things
(1) no decimals
(2) X and Y stuff on the same side and the # by itself.
From (i) subtract 5x to get
(ii) 
This is standard form.
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Equations/255352: how do you write 5580 in scientific notation. 1 solutions
Answer 187618 by drk(1908) on 2010-01-10 13:59:54 (Show Source):
You can put this solution on YOUR website!Notice there is no decimal. IF you don't see one, it is all the way to the right. We want a number expressed in the following form:

where 0 < a < 10 and b is an integer.
step 1 - move the decimal left 3 jumps to get
5.580
step 2 - ask yourself how many jumps and in which direction?
# jumps = 3
direction = left
OUr answer is:
5.580 x 10^3
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Rational-functions/255299: solve using the rational zero theorem and descarte rule:x^4-5x^3-54x^2-80x-32=0 1 solutions
Answer 187617 by drk(1908) on 2010-01-10 13:54:51 (Show Source):
You can put this solution on YOUR website!x^4 - 5x^3 - 54x^2 - 80x - 32 = 0
step 1 - set up P, N, i
P are the number of sign changes you see when (x) is placed into the equation. We get P = 1.
N are the number of sign changes you see when (-x) is placed into the equation. We get N = 3.
Now 1 + 3 = 4.
P . . . 1 . . . . 1
N . . . 3 . . . . 1
i . . . .0 . . . . .2
Notice that i = 0 or 2. Imaginary numbers always travel in conjugate pairs.
Now on to rational zeros. or P/Q
P = +-(1, 2, 4, 8, 16, 32)
Q = +-(1)
We can find that x = -4 and x = -1 give us 2 zeros.
By synthetic division, using x = -4, we get
(x^3-9x^2-18x-8)
and this divided by x = -1 gets us
(x^2-10x-8)
setting this = 0 and solving gets us

or

or simplified as

SO our four answers are:
x = -4, x = -1, x = 5 +-sqrt(33)
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Graphs/255314: Flying against the wind, a plane makes a 1050km trip in 3.5 hours. On the return trip, the flight takes 30 minutes less. What is the rate of the plane in calm air? 1 solutions
Answer 187591 by drk(1908) on 2010-01-10 12:11:30 (Show Source):
You can put this solution on YOUR website!This is an rtd problem with currents. Here is a table based on the given information:
plane . . . . . .rate . . . . . . . . . . . time . . . . .distance
against . . . .r-c=1050 . . . . . . . .3.5 . . . . . . 3675
with . . . . . .r+c . . . . . . . . .. . . .. 3 . . .. . . . .3675
we know
(i) r-c = 1050.
solve with for r+c, we get
(ii) r+c = 1225
adding (i) and (ii) together, we get
(iii) 2r = 2275
r = 1137.5
c then is 87.5 Kph
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Linear-equations/255303: ((x^2 - x) / (x^2 + 3x + 2)) / ((x^2 + 2x)/ (x^2 -1))
or
http://www.thea.nesinc.com/images/math/tasp_image335.gif 1 solutions
Answer 187590 by drk(1908) on 2010-01-10 12:06:45 (Show Source):
You can put this solution on YOUR website!OUr expression is:

step 1 - factor each part separately:
x^2-x = x(x-1)
x^2 + 3x + 2 = (x+2)(x+1)
x^2+ 2x = x(x+2)
x^2-1 = (x+1)(x-1)
we get
 / 
step 2-Multiply the top fraction by the reciprocal of the bottom fraction to get
 * 
step 3 - cancel where possible to get
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Linear-equations/255309: how do you find the slope of a line when your only given two points? we are required to solve it algebralicly with out graphing. i know that there is an equation to solve it but im not sure what it is or how it works. 1 solutions
Answer 187588 by drk(1908) on 2010-01-10 11:59:49 (Show Source):
You can put this solution on YOUR website!Suppose you are given 2 coordinates: A (x1,y1) and B (x2,y2). We can find the slope with the dollowing equation:

--
EX: A(1,4) B (-3,9)
using the slope formula we get
 = 5/-4
so
m = -5/4
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Polynomials-and-rational-expressions/255307: ((C+5)/7)+((C-30)/4)=5/14
I KEEP COMING UP WITH BIG NUMBERS EVEN THOUGHT THE SOLUTION IS SUPPOSED TO BE "1" 1 solutions
Answer 187587 by drk(1908) on 2010-01-10 11:57:09 (Show Source):
You can put this solution on YOUR website!
step 1 - find the common denominator. It is 28.
step 2 - multiply every number by 28 to get

and then

step 3 - combine like terms on the left to get

add 190 to both sides to get

c= 18.1818....
--
checking, we get

3.3116 - 2.9545 ~ .357054 ; 5/14 = .3571428
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Inequalities/255281: n is an integer
a) Write down the values of n which satisfy the inequality
-2 < n ≤ 3
b) Solve the inequality
3x + 2 ≤ 4
Thanks everyone :D 1 solutions
Answer 187559 by drk(1908) on 2010-01-10 09:47:50 (Show Source):
You can put this solution on YOUR website!(a) the values of n are: -1, 0, 1, 2, and 3. We can't use -2 because it is not =.
(b) 3x + 2 ≤ 4
step 1 - subtract 2 to get
3x <=2
step 2 - divide by 3 to get
x<= 2/3
If you want the set of integers then
(- 00, 0]
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Miscellaneous_Word_Problems/255273: A staircase has 5 steps. You can walk up the staircase by taking one or two steps at a time. How many different ways can you walk up the staircase?
1 solutions
Answer 187552 by drk(1908) on 2010-01-10 09:16:14 (Show Source):
You can put this solution on YOUR website!we have
1,1,1,1,1
1,1,1,2
1,1,2,1
1,2,1,1
2,1,1,1
1,2,2
2,1,2
2,2,1
so, it appears we have 8 ways
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Geometric_formulas/255276: A circular archery target is 122 cm in diameter and consists of a bull's eye of diameter 12.2 cm, surrounded by nine evenly spaced concentric circles. Assume that an arrow that hits a target is equally likely to land anywhere on the target. What's the probability that the arrow will A) hit the bulls eye B) Land somewhere in the outmost four circles. C) Land within the fifth ring in from the outer edge. ---Please help on this problem! THANKS! 1 solutions
Answer 187548 by drk(1908) on 2010-01-10 09:07:44 (Show Source):
You can put this solution on YOUR website!Let's call the bulls eye - circle 1 including circle #1, there are 10 concentric circles.
radius of circle 1 = 6.1
radius of circle 2 = 12.2 or 6.1 * 2.
and so on.
A) hit the bulls eye
P(bulls eye) = pi*6.1^2 = 37.21pi cm^2
B) Land somewhere in the outmost four circles.
P(outer 4 circles) = p(whole target - inner 6 circles) = pi*R^2 - pi*r^2 = pi*61^2 -pi*36.6^2.
The 36.6 is the radius of the first 6 circles or 6.1 * 6.
This gives us 2381.44pi cm^2
C) Land within the fifth ring in from the outer edge.
P(5th ring) = p(5th ring - p(4th ring). We want only the fifth ring so all other inner rings must be subtracted out. We get pi*R^2 - pi*r^2 = pi*30.5^2 -pi*24.4^2 = 334.89pi cm^2
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Rectangles/255278: The length of a rectangle is x + 4
The width of a rectangle is x - 1
The perimeter is 46 cm
Calculate the length of the diagonal of the rectangle
Please help?! 1 solutions
Answer 187546 by drk(1908) on 2010-01-10 08:57:30 (Show Source):
You can put this solution on YOUR website!The length of a rectangle is x + 4
The width of a rectangle is x - 1
The perimeter is 46 cm
--
We can use th perimter formula as:
(i) 
replacing x + 4 for L, x - 1 for W, and 46 for P, we get
(ii) 
we solve for x as
(iii) 
(iv) 
(v) 
(vi) 
Now, the length = 14, and the width is 9.
--
Using the Pythagorean theorem:

we get

the diagonal, c, ~ 16.64
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Rectangles/255275: A rectangle has a width of 10 inches and an area of 5 square inches. what is the length of the rectangle? 1 solutions
Answer 187542 by drk(1908) on 2010-01-10 08:43:56 (Show Source):
You can put this solution on YOUR website!We have 1 formula:
(i) A = L x W
step 1 - replace A = 5 and W = 10 to get
(ii) 5 = 10L
step 2 - divide by 10 to get
(iii) 1/2 = L
Length = 1/2 in.
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Parallelograms/255124: How do you find the perimeter of a parallelogram when you have the base of 4m, height of 3m and don't have side length? 1 solutions
Answer 187438 by drk(1908) on 2010-01-09 15:22:14 (Show Source):
You can put this solution on YOUR website!I assume it is isosceles. We can use Pythagorean theorem
a^2 + b^2 = c^2
and then
3^3 + 4^2 = c^2
9 + 16 = c^2
25 = c^2
5 = c.
The perimeter is 3 + 4 + 5 + 5 = 17 m.
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