1 способ:
а) 2 + 4 = 6 б) 8 - 5 = 3
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2 способ:
а) 2 + (2 + 2) = 6 б) 8 - (3 + 2) = 5
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3 способ:
а) 2 + (1 + 1 +1 + 1) = 6 б)(5+3) - 5 = 5 + 3 - 5 = 3