Вычислите 4:2 2/5. 6:1 5/7. 26:1 4/9
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4:2 2/5=4: 12/5=4*5/12=5/3=1 2/3 6:1 5/7=6:12/7=6*7/12=7/2=3 1/2 26:1 4/9=26: 13/9=26*9/13=18