выполни действия (8/9 - 5/6 ) + 2/3 , (7/8 - 13/20) + 9/10 , (7/18 - 1/12) + 5\6

(3/4 - 8/15) + 17/20

(8/9-5/6)+2/3=16/18-15/18+12/18=13/18(7/8-13/20)+9/10=35/40-26/40+36/40=45/40=1 1/8(7/18-1/12)+5/6=14/36-3/36+30/36=41/36=1 5/36(3/4-8/15)+17/20=45/60-32/60+51/60=64/60=1 1/15