• Matéria: Matemática
  • Autor: carolineandreza
  • Perguntado 9 anos atrás

Responde no caderno a seguinte equação
A) 18=x+7
B) 34=3x+7
C) -7x-6x+4=14-3x
D) 5-7x6x=14-9x+5x
E) 3y+2y-5y+12=2y-7y-5y+8
F) 3(y+5)=2(y-8)
G) 3(2y+1)=4y+8
H) 5(s-1)=94-2(s+4)
I) 3(s-4)=80-2(3s+1)

Respostas

respondido por: Anônimo
0
A)
18 = x + 7
18 - 7 = x
11 = x
x = 11

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B)
34 = 3x + 7
34 - 7 = 3x
27 = 3x
3x = 27
x = 27/3
x = 9

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C)

- 7x - 6x + 4 = 14 - 3x
- 13x + 4 = 14 - 3x
4 - 14 = - 3x + 13x
- 10 = 10x
10x = - 10
x = - 10/10
x = - 1

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D)
5 - 7x + 6x =14 - 9x + 5x
5 - x = 14 - 4x
4x - x = 14 - 5
3x = 9
x = 9/3
x = 3

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E)
3y + 2y - 5y + 12 = 2y - 7y - 5y + 8
5y - 5y - 12 = 2y - 12y + 8
- 12 = - 14y + 8
14y = 8 + 12
14y = 20
y =   20  (:2)
      -------
       14   (:2)

y = 10 
      ------
        7

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F)
3.(y + 5) = 2.(y - 8)
3y + 15 = 2y - 16
3y - 2y = - 16 - 15
y = - 31

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G)
3.(2y + 1) = 4y + 8
6y + 3 = 4y + 8
6y - 4y = 8 - 3
2y = 5
y = 5/2

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H)
5.(s - 1) = 94 - 2.(s + 4)
5s - 5 = 94 - 2s - 8
5s - 5 = 86 - 2x
5s + 2s = 86 + 5
7s = 91
s = 91/7
s = 13

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I)

3.(s - 4) = 80 - 2.(3s + 1)
3s - 12 = 80 - 6s - 2
3s -12 = 78 - 6s
3s + 6s = 78 + 12
9s = 90
s = 90/9
s = 10

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