Надо. надо. ( 7целых -2 целых 2/5 *1 целую 7/8) : 5 целых 5/8=

(7 - 2 2/5 * 1 7/8) : 5 5/8 = 4/9

1) 2 2/5 * 1 7/8 = 12/5 * 15/8 = (3*3)/(1*2) = 9/2 = 4 1/2
2) 7 - 4 1/2 = 6 2/2 - 4 1/2 = 2 1/2
3) 2 1/2 : 5 5/8 = 5/2 : 45/8 = 5/2 * 8/45 = (1*4)/(1*9) = 4/9

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