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RAY100 answered: 1636 problems
Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149 , 150..179 , 180..209 , 210..239 , 240..269 , 270..299 , 300..329 , 330..359 , 360..389 , 390..419 , 420..449 , 450..479 , 480..509 , 510..539 , 540..569 , 570..599 , 600..629 , 630..659 , 660..689 , 690..719 , 720..749 , 750..779 , 780..809 , 810..839 , 840..869 , 870..899 , 900..929 , 930..959 , 960..989 , 990..1019 , 1020..1049 , 1050..1079 , 1080..1109 , 1110..1139 , 1140..1169 , 1170..1199 , 1200..1229 , 1230..1259 , 1260..1289 , 1290..1319 , 1320..1349 , 1350..1379 , 1380..1409 , 1410..1439 , 1440..1469 , 1470..1499 , 1500..1529 , 1530..1559 , 1560..1589 , 1590..1619 , 1620..1649, >>Nextlogarithm/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) on 2009-06-11 19:43:08 (Show Source):
You can put this solution on YOUR website!n= p(1)^a(1) + p(2)^a(2) + p(3)^a(3) + .........+ p(k)^a(k)
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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.
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Likewise, the "a" values cannot be negative, leading to a fraction, or a fraction, which would lead to not whole numbers.
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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)
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n = something positive * a number 2 or larger raised to a positive number( making it >2)
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n>2^ k
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and taking log of both sides
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log n > log 2^k or log n > k log 2
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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) on 2009-06-11 19:19:26 (Show Source):
You can put this solution on YOUR website!Probability is the ratio of the number going the desired way, to the total possible numbers'
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something that will not happen has 0 chances / total possible chances., or P=0
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If something is certain, we know all of the chances will be in numerator / same number = 1
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And the P = 1,
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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) on 2009-06-11 18:30:05 (Show Source):
You can put this solution on YOUR website!Let v = # VIP Rings ,,,,and s = # SST Rings
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(1) 3 v + 2 s = 60 hrs
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(2) v + s = 24,,,,,or v = 24 -s
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subst in (1),,,, 3(24-s) +2 s = 60
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72 -3s +2s =60
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12 = s
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v = 24-s=24-12=12,,,,which is answer (C)
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Profit from 12 each is 12(40) + 12 (35) = $ 900, made within guidelines
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Checking the other options
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A) 14(40) +10(35) =$ 910 BUT
checking hrs, 14(3) + 10(2) = 62 hrs,,,,over limit of 60
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B) 12(40) + 8(35) = $ 760,,,,, low
with hrs of 12(3) +8(2) = 52,,, also low
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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) on 2009-06-11 17:17:52 (Show Source):
You can put this solution on YOUR website!A(x) = x^2 +5x +6
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a(5) = (5)^2 + 5(5) +6 = 56
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A(x) = x^2 +5x +6 = 1/2 ( h) (l) = (1/2) (x+3) h,,,,,,,area of triangle = 1/2 base * height
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{ (x+3)(x+2) } / (1/2) ( x+3) = 2(x+2) = h
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check
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A(5) = 56, (x+3)= 8,, A = 1/2 * 8 * h = 56,,,,,h= 112/8 = 14
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h=2(x+2) = 2 (5+2) =14,,,,,,ok
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Polynomials-and-rational-expressions/199786: Please help me solve this problem 2x^2-14x+3x-21 1 solutions
Answer 150157 by RAY100(1637) on 2009-06-11 16:04:58 (Show Source):
You can put this solution on YOUR website!when there are four terms, try factoring by grouping
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2x^3 -14x +3x -21
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2x (x-7) +3(x-7},,,,,,like ab +cb= (a+c)b ,,,but b=(x-7)
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(2x+3) (x-7)
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check by subst x=1 in original and answer, ok
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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) on 2009-06-11 12:57:04 (Show Source):
You can put this solution on YOUR website!for 3 times around, let Distance = 3 * Circumference
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d = 3 * 2 *pi * radius, radius = 1500 / 2 = 750
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d = 3 * 2 * 3.14 * 750 = 14,130 ft
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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) on 2009-06-11 12:51:59 (Show Source):
You can put this solution on YOUR website!If total budget is $ 520,000, and taxes are 15 %
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.15 * $520, 000 = $ 78,000
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check,,,,78 /520 =.15 ,,,,ok
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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) on 2009-06-11 12:47:57 (Show Source):
You can put this solution on YOUR website!to factor ,,,x^3 -4x^2 +x +6,,,,knowing (x+1) is a factor,,,,use poly division or synthetic division
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,,,,,,-1,,,,1,,,,-4,,,,,+1,,,,6
,,,,,,,,,,,,,,,,,,,-1,,,,,+5,,,-6
,,,,,,,,,,,,,,,__________________
,,,,,,,,,,,,,,1,,,,-5,,,,+6,,,,,0
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(x+1)(x^2 -5x +6),,,,,,,now just factor 2nd term
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(x+1) ( x-3) (x-2),,,,,or answer B
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to check, multiply factors to reach original,,,,ok
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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) on 2009-06-11 09:09:01 (Show Source):
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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) on 2009-06-11 09:02:40 (Show Source):
You can put this solution on YOUR website!(1) 4x +5x -10 = 35
9x -10 =35,,,,,combining like terms
9x =45,,,,,,,,adding 10 to both sides
x=5,,,,,,,,,,,,,dividing by 9
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(2) 9x+6x-12x = -7x +2x -12 +5x
3x = -12,,,,,,,,,combining like terms
x= -4,,,,,,,,dividing by 3
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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) on 2009-06-11 08:52:44 (Show Source):
You can put this solution on YOUR website!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.
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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.
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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.
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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
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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) on 2009-06-08 14:24:08 (Show Source):
You can put this solution on YOUR website![ 7^(n+2) -35*7^9n-1)] / [ 44(7^(n+2) ) ] = 1/49
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[ 1-35*7^-3] / 44 = 1/49
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[ 1 - 35 / (49*7) ] / 44 = 1/49
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[ 1-5/49] / 44 = 1/49
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[49/49 -5/49 ] / 44 = 1/49
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[ 44 / 49 ] / 44 = 1/49
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(44/49) * (1/44) = 1/49 = 1/49,,,,,,ok
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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) on 2009-06-08 14:07:01 (Show Source):
You can put this solution on YOUR website!Remember negative exponent is reciprocal,,,,a^-2 = 1/a^2
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AND , to divide common bases,,,substract exponents,,,,a^4/a^2=a^(4-2) = a^2
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(1) (r^-4)(-6r^2t^2) = -6 r^-2t^2= -6t^2 / r^2
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(2) w^3 / (-6w^-6) = w^9/-6 = (-1/6) w^9
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(3) k^6 / (k^3)^5 = k^6/k^15 =k^-9 = 1/k^9
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(4) t^-9 / q^-9 = q^9/t^9 = (q/t)^9
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check by assigning numbers to variables and checking original and answer,,,all ok
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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) on 2009-06-08 13:13:42 (Show Source):
You can put this solution on YOUR website!Remember,,, form y= a(n)x^n +..... / b(m) x^m +......
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for VERTICAL ASYMPTOTES,,,,,,find zero"s of denominator
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in all 3 cases above,,, (x-2) =0,,,or x=2 is a vertical asymptote
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For HORIZONTAL ASYMPTOTES,,,,
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if n less than m,,,,,,y=0
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if n=m,,,,,y = a(n)/b(m)
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n>m,,,,,,, no horizontal asymptote
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In the 1st case,,, n=0,m=1,,,or n is less than m,,,,,y=0 is hor asymptote
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in the 2nd case,,,n=1,m=1,,or n=m,,,,y = a(n)/b(m) = 1/1 =1,,,, y=1 is hor asymptote
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in the 3rd case, n=2,m=1 ,,or n>m,,,,,therefore no hor asymptote
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for OBLIQUE ASYMPTOTES (SLANT)
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if n=(m+1),,,divide numerator by denominator ,,,,and set answer (without remainder) =y
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in the 3rd case above ,,,n=2,m=1,,or n=(m+1),,,,therefore there is a SLANT asymptote
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( x^2 +x -2) / (x-2) = x+3 +4/(x-2)
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setting y = x+3,,,,,,for slant asymptote
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.We might also look for x intercepts,,,,which are zero's of numerator.
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case 2 ,,,has one at x=-2
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case 3,,,has one at x=-2,,and another at x=+1
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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) on 2009-06-08 12:39:10 (Show Source):
You can put this solution on YOUR website!There are actually two parabolas that meet this criteria, a "y" parabola, and an "x" parabola
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the standard form for a "y" parabola is ,,,, ( y-k) = a (x-h)^2, where (h,k) is the vertex
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substituting our data,,,, vertex at (5, -7) and (4,1),,,,, ( y-(-7) ) = a (x-5)^2
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@ ( 4,1),,,, (1) +7 =a ( 4-5)^2,,,,8=a(1),,,, a=8
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"y" parabola is y+7 = 8(x-5)^2,,,or y= 8(x-5)^2 -7
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to check substitute in both given points,,,ok
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The standard form for an "x" parabola is,,,,,(x-h) =a ( y-k)^2
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or (x-5) = a (y+7)^2,,,,,and @ (4,1),,,,, (4-5) = a (1+7)^2,,,,a= -1/64
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or (x-5) = -1/64 (y+7)^2,,,,,or x= -1/64 (y+7) ^2 +5
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to check substitute in both sets of points,,,,,,ok
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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) on 2009-06-08 11:59:50 (Show Source):
You can put this solution on YOUR website!Let x = velocity in still water
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Distance = Velocity * Time
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D1 = (x+6) 5 = 5x +30
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D2 = (x-6) 10 = 10x -60
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but D1 = D2
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5x +30 = 10x -60
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90 = 5x
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18 = x
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checking
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(18 +6) * 5 = (18-6) 10
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120 =120,,,,ok
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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) on 2009-06-08 11:49:59 (Show Source):
You can put this solution on YOUR website!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
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vol = ( 1.2 *1.2 ) * 2 = 2.88 sq meters
,
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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) on 2009-06-08 10:05:49 (Show Source):
You can put this solution on YOUR website!Remember that Area = pi * rad^2
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we are given diameter = 42, or radius = 21 ,,,,(42/2)
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Area = pi * r^2 = pi * 21^2 = pi * 441 = 1385.44 inches ^2
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an obscure Area formula is A = pi d^2 /4 = pi 42^2 /4 = 1385.44 also
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