Fazendo mmc no numerador da fração:
(60x + 30x + 20x + 15x + 12x / 60 ) / (1 + 2 + 3 + 4 + 5 / x) = 137
(137x / 60) / (15 / x) = 137
137x² / 900 = 137
Dividindo os dois lados da equação por 137:
x² / 900 = 1
x² = 900
x = +-30
Verificando as respostas:
Para x = +30:
(30/1 + 30/2 + 30/3 + 30/4 + 30/5) / (1 + 2 + 3 + 4 + 5 / 30) = 137
(30 + 15 + 10 + 7.5 + 6) / (15 / 30) = 137
68.5 / (1 / 2) = 137
137 = 137
OK!!
Para x = -30:
(-30 - 15 - 10 - 7.5 - 6) / (-15 / 30) = 137
-68.5 / (-1 / 2) = 137
137 = 137
OK!!!!
Portanto:
S={-30;+30}
Flw!
2007-12-09 22:46:09
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answer #1
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answered by Ark 4
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x/1 + x/2 + x/3 + x/4 + x/5 = x(1 +1/2 +1/3 + 1/4 + 1/5) = x(60 + 30 + 20 + 15 + 12)/60 = 137x/60 (mmc(1,2,3,4,5) = 60)
1/x + 2/x + 3/x + 4/x + 5/x = 15/x
Logo,
(x/1 + x/2 + x/3 + x/4 + x/5) / (1/x + 2/x + 3/x + 4/x + 5/x)
= (137x/60)/(15/x) = 137x/60 * x/15 = (137x^2)/900 = 137.
Assim, x^2/900 = 1 => x^2 = 900, havendo portanto 2 soluções, x = + ou - raiz(900), ou seja, x = 30 e x = -30
O conjunto silução é {-30, 30}
2007-12-09 23:34:07
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answer #2
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answered by Steiner 7
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(x/1 + x/2 + x/3 + x/4 + x/5) / (1/x + 2/x + 3/x + 4/x + 5/x) = 137
(x/1 + x/2 + x/3 + x/4 + x/5) / (1+2+3+4+5/x ) = 137
(x/1 + x/2 + x/3 + x/4 + x/5) / (15/x ) = 137
MMC = 1*2*3*4*5 = 120
(120x + 60x + 40x + 30x + 24x/120) / (15/x ) = 137
(274x/120) / (15/x ) = 137
(274x/120) * (x/15 ) = 137
274x²/1800 = 137
137x²/900 = 137
137x² = 137*900
x² = (137*900)/137
x² = 900
x = + - 30
Resposta: x={-30,+30}
Conferindo:
(x/1 + x/2 + x/3 + x/4 + x/5) / (1/x + 2/x + 3/x + 4/x + 5/x) =
(-30/1 -30/2 -30/3 -30/4 -30/5) / (1/-30 + 2/-30 + 3/-30 + 4/-30 + 5/-30) =
(-30 -15 -10 -7,5 -6) / (-1-2-3-4-5/30) =
(-30 -15 -10 -7,5 -6) / (-1-2-3-4-5/30) =
-68,5 / (-15/30) =
-68,5 / (-1/2) =
-68,5 * -2 =
137
(x/1 + x/2 + x/3 + x/4 + x/5) / (1/x + 2/x + 3/x + 4/x + 5/x) =
(30/1 + 30/2 + 30/3 + 30/4 + 30/5) / (1/30 + 2/30 + 3/30 + 4/30 + 5/30) =
(30 +15 +10 +7,5 +6) / (1+2+3+4+5/30) =
68,5 / (15/30) =
68,5 / (1/2) =
68,5 * 2 =
137
Kisses
=**
2007-12-09 22:44:16
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answer #3
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answered by Math Girl 7
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é 1 bilhão, seiscentos e cinquenta e sete trilhões ^^
54321654321564654654621
essa é a resposta final ^^
2007-12-09 22:33:08
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answer #4
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answered by Anonymous
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