Question

resolva as equações a seguir (contas por favor) : 1) 2.(3x-1) + 2.(3-x) = 0 2) 7.(x-1) = 2.(3x+1) 3) 2.(3-y) + 7.(2-y) = 15 - 4y 4) 2.(x-2) + 5.(2-x) + 6.(x+1) = 0 5) 3.(x-2) - (1-x) = 13 6) x - (x+1) = 12 - (3x-2) 7) x/2 = 12/3 8) 2x/3 + 1/2 = x/4 - 3/2 9) x/3 - 1 + 3/4 = x/2 - 1/4

Answer 1

1) 2.(3x-1) + 2.(3-x) = 0
6x - 2 + 6 - 2x = 0
4x = -4
x = -1

2) 7.(x-1) = 2.(3x+1)
7x - 7 = 6x + 2
7x - 6x = 2 + 7
x = 9

3) 2.(3-y) + 7.(2-y) = 15 - 4y
6 - 2y + 14 - 7y = 15 - 4y
-2y - 7y + 4y = 15 - 14 - 6
-5y = -5
y = -5/-5
y = 1

4) 2.(x-2) + 5.(2-x) + 6.(x+1) = 0
2x - 4 + 10 - 5x + 6x + 6 = 0
3x = -12
x = -12/3
x = -4

5) 3.(x-2) - (1-x) = 13
3x - 6 - 1 + x = 13
4x = 13 + 7
x = 20/4
x = 5

6) x - (x+1) = 12 - (3x-2)
x - x - x = 12 - 3x + 2
-x + 3x = 12 + 2
2x = 14
x = 14/2
x = 7

7) x/2 = 12/3
3x = 12.2
x = 24/3
x = 8

8) 2x/3 + 1/2 = x/4 - 3/2
mmc(2,3,4) = 12
(8x + 6 = 3x - 18) / 12
8x + 6 = 3x - 18
8x - 3x = - 18 - 6
5x = -24
x = -24/5

9) x/3 - 1 + 3/4 = x/2 - 1/4
mmc(2, 3, 4) = 12
(4x - 12 + 9 = 6x - 3)/12
4x - 12 + 9 = 6x - 3
4x - 6x = - 3 + 12 - 9
-2x = 0
x = 0

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