Ответ:

1) -1

2) -1

3) -1

4) -1

Пошаговое объяснение:

1) (5/6 - 1/3) / (1/3 - 5/6) = (5/6 - 2/6) / (2/6 - 5/6) = (3/6) / (-3/6) = -1

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2) (1/2 - 2/3) / (2/3 - 1/2) = (3/6 - 4/6) / (4/6 - 3/6) = (-1/6) / (1/6) = -1

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3) (1,7 - 2) / (2 - 1,7) = -0,3/0,3 = -1

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4) (0,9 - 3) / (3 - 0,9) = -2,1/2,1 = -1

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