5 5/7*5/12*5 1/4*6/7:1 1/2

40/7*5/12*21/4*6/7:3/2= (40/7*21/4)*(5/12*6/7)*2/3= (10*3)*(5/2*1/7)*2/3= 30*5/14*2/3= 10*5/7=50/7= 7 1/7

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