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RAY100 answered: 1636 problems
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logarithm/199745: if n is a natural number such that n=p1 power a1 *p2 power a2*p3 power a3..............*pk power ak and pk are distinct primes , then show that log n>=k log2
1 solutions

Answer 150190 by RAY100(1637) About Me  on 2009-06-11 19:43:08 (Show Source):
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n= p(1)^a(1) + p(2)^a(2) + p(3)^a(3) + .........+ p(k)^a(k)
.
n is a natural number,,,this leads to n=1 or larger integer. ,,,, AND it limits each term of the sequence to a positive number. That is, the p"s cannot be + or -, as this would restrict the terms to an even number, to make n positive, which was not stated.
.
Likewise, the "a" values cannot be negative, leading to a fraction, or a fraction, which would lead to not whole numbers.
.
The given that p(k) is a distinct prime, leads to the min value of p(k) being the min prime, or 2 .,,,or larger,,, (1 is a special number, not prime)
.
n = something positive * a number 2 or larger raised to a positive number( making it >2)
.
n>2^ k
.
and taking log of both sides
.
log n > log 2^k or log n > k log 2


Linear_Equations_And_Systems_Word_Problems/199742: Explain in your own words, using the definition of probability why: a) the probability of an event that cannot occur is 0; b) the probability of an event that must occur is 1.
1 solutions

Answer 150188 by RAY100(1637) About Me  on 2009-06-11 19:19:26 (Show Source):
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Probability is the ratio of the number going the desired way, to the total possible numbers'
.
something that will not happen has 0 chances / total possible chances., or P=0
.
If something is certain, we know all of the chances will be in numerator / same number = 1
.
And the P = 1,


Expressions-with-variables/199722: Can someone please help me with this:
The Acme Class Ring Company designs and sells two types fo rings: the VIP and the SST. They can produce up to 24 rings each day using up to 60 total man-hours of labor. Its takes 3 man-hours to make one VIP ring versus 2 man-hours to make one SST ring.
How many of each type of ring should be made daily to maximize the companys profit, if the profit on a VIP ring is $40 and an SST ring is $35?
a. 14 VIP AND 10 SST
b. 16 VIP AND 8 SST
c. 12 VIP AND 12 SST
1 solutions

Answer 150174 by RAY100(1637) About Me  on 2009-06-11 18:30:05 (Show Source):
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Let v = # VIP Rings ,,,,and s = # SST Rings
,
(1) 3 v + 2 s = 60 hrs
.
(2) v + s = 24,,,,,or v = 24 -s
.
subst in (1),,,, 3(24-s) +2 s = 60
.
72 -3s +2s =60
.
12 = s
.
v = 24-s=24-12=12,,,,which is answer (C)
.
Profit from 12 each is 12(40) + 12 (35) = $ 900, made within guidelines
.
Checking the other options
.
A) 14(40) +10(35) =$ 910 BUT
checking hrs, 14(3) + 10(2) = 62 hrs,,,,over limit of 60
.
B) 12(40) + 8(35) = $ 760,,,,, low
with hrs of 12(3) +8(2) = 52,,, also low


Human-and-algebraic-language/199746: area of a sale. The area of in square meters for a triangular sale is given by A(x)=x^2+5x+6 Find A(5), if the hignt of the sail is x+3 meters, then what is the lenght of the sail?
1 solutions

Answer 150171 by RAY100(1637) About Me  on 2009-06-11 17:17:52 (Show Source):
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A(x) = x^2 +5x +6
.
a(5) = (5)^2 + 5(5) +6 = 56
.
A(x) = x^2 +5x +6 = 1/2 ( h) (l) = (1/2) (x+3) h,,,,,,,area of triangle = 1/2 base * height
.
{ (x+3)(x+2) } / (1/2) ( x+3) = 2(x+2) = h
.
check
.
A(5) = 56, (x+3)= 8,, A = 1/2 * 8 * h = 56,,,,,h= 112/8 = 14
.
h=2(x+2) = 2 (5+2) =14,,,,,,ok


Linear-equations/199790: What is the y-intercept of 3x - 2y = 0
1 solutions

Answer 150169 by RAY100(1637) About Me  on 2009-06-11 17:07:17 (Show Source):
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3x -2y =0
.
to find y intercept ,,,let x =0 ( and vice versa )
.
at x=0, y=0,,,y intercept is y=0


Polynomials-and-rational-expressions/199786: Please help me solve this problem 2x^2-14x+3x-21
1 solutions

Answer 150157 by RAY100(1637) About Me  on 2009-06-11 16:04:58 (Show Source):
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when there are four terms, try factoring by grouping
.
2x^3 -14x +3x -21
.
2x (x-7) +3(x-7},,,,,,like ab +cb= (a+c)b ,,,but b=(x-7)
.
(2x+3) (x-7)
.
check by subst x=1 in original and answer, ok


Linear-equations/199769: A circular path around a lake has a diameter of 1,500 feet (ft). Pranotti jogs around the path 3 times for her morning run. How far does she run? Use 3.14 for and round your answer to the nearest foot.
1 solutions

Answer 150127 by RAY100(1637) About Me  on 2009-06-11 12:57:04 (Show Source):
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for 3 times around, let Distance = 3 * Circumference
.
d = 3 * 2 *pi * radius, radius = 1500 / 2 = 750
.
d = 3 * 2 * 3.14 * 750 = 14,130 ft


percentage/199770: The following pie chart shows the budget for a local company. The total budget is $520,000. Find the actual amount budgeted in the category of Taxes.


Research 10%
Production 40%
operating expense 25%
Taxes 15%
Miscellaneous 10%
1 solutions

Answer 150126 by RAY100(1637) About Me  on 2009-06-11 12:51:59 (Show Source):
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If total budget is $ 520,000, and taxes are 15 %
.
.15 * $520, 000 = $ 78,000
.
check,,,,78 /520 =.15 ,,,,ok
.


Polynomials-and-rational-expressions/199766: Factor the polynomial below completely, given that the binomial following it is a factor of the polynomial.
x^3-4x^2+x+6, x+1
A) (x+1)(x^2-5x+6)
B) (x+1)(x-3)(x-2)
C) (x+1)(x-3)(x+2)
D) (x+1)(x+3)(x-2)
1 solutions

Answer 150125 by RAY100(1637) About Me  on 2009-06-11 12:47:57 (Show Source):
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to factor ,,,x^3 -4x^2 +x +6,,,,knowing (x+1) is a factor,,,,use poly division or synthetic division
.
,,,,,,-1,,,,1,,,,-4,,,,,+1,,,,6
,,,,,,,,,,,,,,,,,,,-1,,,,,+5,,,-6
,,,,,,,,,,,,,,,__________________
,,,,,,,,,,,,,,1,,,,-5,,,,+6,,,,,0
.
(x+1)(x^2 -5x +6),,,,,,,now just factor 2nd term
.
(x+1) ( x-3) (x-2),,,,,or answer B
.
to check, multiply factors to reach original,,,,ok


Polynomials-and-rational-expressions/199767: Translate the verbal expression into an algebraic expression:
The difference of n and the square of k
A) (n-k)^2
B) n^2 - k
C) n-k^2
D) -n*k^2
1 solutions

Answer 150124 by RAY100(1637) About Me  on 2009-06-11 12:34:53 (Show Source):
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difference is subtraction
.
( n ) - ( k^2 )
.
therefore c) n-k^2
.


Circles/199723: Two chords of a circle are perpendicular and congruent, does one of them have a diameter?
1 solutions

Answer 150111 by RAY100(1637) About Me  on 2009-06-11 09:22:55 (Show Source):
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Please see answer to problem # 199732 thanks


Circles/199724: Two chords of a circle are perpendicular and congruent, does one of them have a diameter?
1 solutions

Answer 150109 by RAY100(1637) About Me  on 2009-06-11 09:21:19 (Show Source):
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Please see answer to problem # 199732 thanks


Circles/199725: Two chords of a circle are perpendicular and congruent, does one of them have a diameter?
1 solutions

Answer 150108 by RAY100(1637) About Me  on 2009-06-11 09:19:48 (Show Source):
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Please see answer to problem # 199732 thanks


Circles/199726: Two chords of a circle are perpendicular and congruent, does one of them have a diameter?
1 solutions

Answer 150107 by RAY100(1637) About Me  on 2009-06-11 09:18:14 (Show Source):
You can put this solution on YOUR website!
Please see answer to problem # 199732 thanks


Circles/199727: Two chords of a circle are perpendicular and congruent, does one of them have a diameter?
1 solutions

Answer 150106 by RAY100(1637) About Me  on 2009-06-11 09:17:01 (Show Source):
You can put this solution on YOUR website!
Please see answer to problem # 199732 thanks


Circles/199728: Two chords of a circle are perpendicular and congruent, does one of them have a diameter?
1 solutions

Answer 150105 by RAY100(1637) About Me  on 2009-06-11 09:13:44 (Show Source):
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please see solution to problem # 199732 thanks


Geometry_proofs/199731: Given: TR ≅ TY
Prove: ΔTRY is isosceles.
Choose the corresponding reason for each statement.
1. TR ≅ TY
2. TR=TY
3. ΔTRY is isosceles.
1 solutions

Answer 150103 by RAY100(1637) About Me  on 2009-06-11 09:09:01 (Show Source):
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1. given
.
2 definition of congruence (sides of equal length)
.
3 definition of an isosceles triangle ( 2 sides equal)


Equations/199735: solve each equation, is whats in my book.
4x+5x-10=35
and
9x +6x-12x= -7x+2x-12+5x
1 solutions

Answer 150102 by RAY100(1637) About Me  on 2009-06-11 09:02:40 (Show Source):
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(1) 4x +5x -10 = 35
9x -10 =35,,,,,combining like terms
9x =45,,,,,,,,adding 10 to both sides
x=5,,,,,,,,,,,,,dividing by 9
.
(2) 9x+6x-12x = -7x +2x -12 +5x
3x = -12,,,,,,,,,combining like terms
x= -4,,,,,,,,dividing by 3
.


Circles/199732: Two chords of a circle are perpendicular and congruent, does one of them have a diameter?
1 solutions

Answer 150100 by RAY100(1637) About Me  on 2009-06-11 08:52:44 (Show Source):
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Very interesting question
Let's start with a rough sketch of a circle, now one chord, now another perpendicular chord that goes thru center.
This is the situation that answers your question, yes it can happen but it does not have to.
.
The principle that puts the second chord thru the center is,,,, it must be a perpendicular bisector. ALL perp bisectors go thru center, hence could be diameters.
.
It is easy to take your sketch, and just slide the second chord to one side or the other. It does not go thru center, and is not a diameter. Your problem did not specify bisection.
.
Another interesting construction, again draw a rough circle and one chord. Draw a second chord, perpendicular to first but located at an end of the first chord. NOW, if we connect the other ends of the chord, we have a triangle. But, a very special triangle, it is a right inscribed triangle, that divides the circle into two semicircles, and has the hypotenuse as the diameter.
Good luck with class


logarithm/199294: Prove that 7^(n+2)-35(7^n-1)/44(7^n+2) is equal to 1/49
1 solutions

Answer 149806 by RAY100(1637) About Me  on 2009-06-08 14:24:08 (Show Source):
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[ 7^(n+2) -35*7^9n-1)] / [ 44(7^(n+2) ) ] = 1/49
.
[ 1-35*7^-3] / 44 = 1/49
.
[ 1 - 35 / (49*7) ] / 44 = 1/49
.
[ 1-5/49] / 44 = 1/49
.
[49/49 -5/49 ] / 44 = 1/49
.
[ 44 / 49 ] / 44 = 1/49
.
(44/49) * (1/44) = 1/49 = 1/49,,,,,,ok


Polynomials-and-rational-expressions/199341: 1.) (r^-4) ( -6r^2t^2)
2.) w^3 / -6w^-6
3.) (k^6) (k^3)^5
4.) t^-9 / g^-9
1 solutions

Answer 149804 by RAY100(1637) About Me  on 2009-06-08 14:07:01 (Show Source):
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Remember negative exponent is reciprocal,,,,a^-2 = 1/a^2
.
AND , to divide common bases,,,substract exponents,,,,a^4/a^2=a^(4-2) = a^2
.
(1) (r^-4)(-6r^2t^2) = -6 r^-2t^2= -6t^2 / r^2
.
(2) w^3 / (-6w^-6) = w^9/-6 = (-1/6) w^9
.
(3) k^6 / (k^3)^5 = k^6/k^15 =k^-9 = 1/k^9
.
(4) t^-9 / q^-9 = q^9/t^9 = (q/t)^9
.
check by assigning numbers to variables and checking original and answer,,,all ok


expressions/199349: 4(P-9)=64
1 solutions

Answer 149803 by RAY100(1637) About Me  on 2009-06-08 13:50:49 (Show Source):
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4(p-9) =64
.
p-9 = 64/4 = 16
.
p =16 +9 =25
.
check
.
4(25-9) =64
.
4(16) =64,,,,,ok


Rational-functions/199343: Give the equations of any vertical,horizontal, or oblique asymptotes.
1.f(x)= 1/x-2
2.f(x)= x+2/x-2
3.f(x)= x^2+x-2/x-2
1 solutions

Answer 149802 by RAY100(1637) About Me  on 2009-06-08 13:47:38 (Show Source):
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please see problem 199342


expressions/199345: if y times 1 minus x=z than what is x?
1 solutions

Answer 149801 by RAY100(1637) About Me  on 2009-06-08 13:42:34 (Show Source):
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y * (1-x) = z
.
y-xy =z
.
-xy = z -y
.
x = (z-y) / ( -y) = -z/y +1 =1-z/y
.
check by letting x=4, y=2, then z=-6,,,,ok for both original and answer


expressions/199346: -6r + s - rs r=5 s=7
1 solutions

Answer 149799 by RAY100(1637) About Me  on 2009-06-08 13:33:47 (Show Source):
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-6r +s -rs
.
r(-6-s) +s
.
5(-6-7) +7
.
5(-13) +7
.
-65 +7
.
-58
.
check using direct subst into initial eqn
.
-6(5)+(7) -(5)(7) = -30 +7 -35 = -65 +7 =-58,,,,ok


Rational-functions/199342: Give the equations of any vertical,horizontal, or oblique asymptotes.
1.f(x)= 1/x-2
2.f(x)= x+2/x-2
3.f(x)= x^2+x-2/x-2
1 solutions

Answer 149796 by RAY100(1637) About Me  on 2009-06-08 13:13:42 (Show Source):
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Remember,,, form y= a(n)x^n +..... / b(m) x^m +......
.
for VERTICAL ASYMPTOTES,,,,,,find zero"s of denominator
.
in all 3 cases above,,, (x-2) =0,,,or x=2 is a vertical asymptote
.
For HORIZONTAL ASYMPTOTES,,,,
.
if n less than m,,,,,,y=0
.
if n=m,,,,,y = a(n)/b(m)
.
n>m,,,,,,, no horizontal asymptote
.
In the 1st case,,, n=0,m=1,,,or n is less than m,,,,,y=0 is hor asymptote
.
in the 2nd case,,,n=1,m=1,,or n=m,,,,y = a(n)/b(m) = 1/1 =1,,,, y=1 is hor asymptote
.
in the 3rd case, n=2,m=1 ,,or n>m,,,,,therefore no hor asymptote
.
for OBLIQUE ASYMPTOTES (SLANT)
.
if n=(m+1),,,divide numerator by denominator ,,,,and set answer (without remainder) =y
.
in the 3rd case above ,,,n=2,m=1,,or n=(m+1),,,,therefore there is a SLANT asymptote
.
( x^2 +x -2) / (x-2) = x+3 +4/(x-2)
.
setting y = x+3,,,,,,for slant asymptote
.
.We might also look for x intercepts,,,,which are zero's of numerator.
.
case 2 ,,,has one at x=-2
.
case 3,,,has one at x=-2,,and another at x=+1
.


Functions/199338: Hello!
Find a function whose graph is a parabola with vertex (5, -7) and that passes through the point (4, 1).
thanks for your help!
1 solutions

Answer 149795 by RAY100(1637) About Me  on 2009-06-08 12:39:10 (Show Source):
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There are actually two parabolas that meet this criteria, a "y" parabola, and an "x" parabola
.
the standard form for a "y" parabola is ,,,, ( y-k) = a (x-h)^2, where (h,k) is the vertex
.
substituting our data,,,, vertex at (5, -7) and (4,1),,,,, ( y-(-7) ) = a (x-5)^2
.
@ ( 4,1),,,, (1) +7 =a ( 4-5)^2,,,,8=a(1),,,, a=8
.
"y" parabola is y+7 = 8(x-5)^2,,,or y= 8(x-5)^2 -7
.
to check substitute in both given points,,,ok
.
The standard form for an "x" parabola is,,,,,(x-h) =a ( y-k)^2
.
or (x-5) = a (y+7)^2,,,,,and @ (4,1),,,,, (4-5) = a (1+7)^2,,,,a= -1/64
.
or (x-5) = -1/64 (y+7)^2,,,,,or x= -1/64 (y+7) ^2 +5
.
to check substitute in both sets of points,,,,,,ok


Travel_Word_Problems/199340: Fred paddled for 5 hours with a 6km/hr current to reach a campsite. The return trip against the same current took 10 hours. Find the speed of Fred's canoe in still water.
1 solutions

Answer 149793 by RAY100(1637) About Me  on 2009-06-08 11:59:50 (Show Source):
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Let x = velocity in still water
.
Distance = Velocity * Time
.
D1 = (x+6) 5 = 5x +30
.
D2 = (x-6) 10 = 10x -60
.
but D1 = D2
.
5x +30 = 10x -60
.
90 = 5x
.
18 = x
.
checking
.
(18 +6) * 5 = (18-6) 10
.
120 =120,,,,ok


Points-lines-and-rays/199329: I need your assistant again I miss this one on my quiz and I need to know the correct way to do this.
Find the volume of a refrigerator that is a rectangular solid and is 2 meter tall and has a base that is 1.2 meters square.
thank you so much!!!!!!!!!!!!!!!!!!!!
1 solutions

Answer 149792 by RAY100(1637) About Me  on 2009-06-08 11:49:59 (Show Source):
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Remember that the volume of a rectangular solid, or prism ,,,,Vol = B * h,,,, where B is the Area of the base,,,,and h is the height
.
vol = ( 1.2 *1.2 ) * 2 = 2.88 sq meters
,


expressions/199332: 8x+2=7(x-4)+6
1 solutions

Answer 149784 by RAY100(1637) About Me  on 2009-06-08 11:03:15 (Show Source):
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Remember order of operations
.
8x +2 = 7(x-4) +6
.
8x +2 = 7x -28 +6
.
8x -7x = -2 -28 +6
.
x= -24
.
check
.
8( -24) +2 = 7( ( -24) -4 ) +6
.
-192 +2 = -196 +6
.
-190 = -190,,,,,,ok
.


Points-lines-and-rays/199331: I'm having a really hard time figuring this problem out please help
What is the area in feet of circular tablecloth that has a diameter of 42 inches?
1 solutions

Answer 149781 by RAY100(1637) About Me  on 2009-06-08 10:05:49 (Show Source):
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Remember that Area = pi * rad^2
.
we are given diameter = 42, or radius = 21 ,,,,(42/2)
.
Area = pi * r^2 = pi * 21^2 = pi * 441 = 1385.44 inches ^2
.
.
an obscure Area formula is A = pi d^2 /4 = pi 42^2 /4 = 1385.44 also
.