F.1數學,,,,十萬火急急急急急

1)

8x - 3 = 4x - 5

8x - 4x = - 5 + 3

4x = -2

2x = -1

x = -1/2

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2)

7(1.2 - k) = 14k

8.4 - 7k = 14k

-7k - 14k = -8.4

21k = 8.4

k = 0.4

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3)

(3/2)c = -3(3c + 1)

2(3/2)c = 2[-3(3c + 1)]

3c = -6(3c + 1)

3c = -18c - 6

3c + 18c = -6

21c = -6

7c = -2

c = -2/7

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4)

-6(3 - 2n) = 5(n - 2)

-18 + 12n = 5n - 10

12n - 5n = -10 + 18

7n = 8

n = 8/7

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5)

4[3(y - 2) + 1] = -14

12(y - 2) + 4 = -14

12y - 24 + 4 = -14

12y - 20 = -14

12y = -14 + 20

12y = 6

2y = 1

y = 1/2

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6)

2[a - (1 - a)] = 3(a - 1) + 8

2[a - 1 + a] = 3a - 3 + 8

2(2a - 1) = 3a + 5

4a - 2 = 3a + 5

4a - 3a = 5 + 2

a = 7

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