12,3 - у = - 16
- у = -12,3 - 16
у = 28,3
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Проверка:
12,3 - 28,3 = - 16
- 16 = - 16
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t -(-7 16/21) = - 1 5/14
t + 7 16/21 = - 1 5/14
t = - 1 5/14 - 7 16/21
t = - 19/14 - 163/21
t = - 57/42 - 326/42
t = - 383/42
t = - 9 5/42
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Проверка:
- 9 5/42 + 7 16/21 = - 1 5/14
- 383/42 + 326/42 = - 57/42
- 57/42 = - 57/42