35 = 5 . 7 sau 7 . 5 sau 1 . 35 sau 35 . 1
2x + 1 = 5, deci x = 2
9-3y = 7, deci y = 2/3
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2x + 1 = 7, deci x = 3
9-3y = 5, deci y = 4/3
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2x + 1 = 1, deci x = 0
9-3y = 35
deci y = -26/3
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2x + 1 = 35, deci x = 17
9-3y = 1, deci y = 8/3