1)75/100*34/3-89/10:89/11=3/4*34/3-89/10*11/89=34/4-11/10=(170-22)/20=148/20=
=7 2/5=7,4
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2)91/6:182/10+13/100*92/13=91/6*10/182+13/100*92/13=5/6+92/100=5/6+23/25=
=(125+138)/150=263/150=1 113/150
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978/10:489/23-1/47*94/3=978/10*23/489-1/47*94/3=46/10-2/3=(138-20)/30=118/30=
=3 28/30=3 14/15
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470/7:10/7+334/10:167/19=470/7*7/10+334/10*19/167=470/10+38/10=508/10=50 4/5